docs: add comprehensive multi-language documentation (en-US + pt-BR)

QRCoder.Core/Abstractions/AbstractQRCode.cs

@@ -5,17 +5,18 @@ namespace QRCoder.Core.Abstractions
     using QRCoder.Core.Models;
 
     /// <summary>
-    /// AbstractQRCode
+    /// Abstract base class for all QR code renderers. Provides shared lifecycle management
+    /// and access to the underlying <see cref="QRCodeData"/> used for rendering.
     /// </summary>
     public abstract class AbstractQRCode : IDisposable
     {
         /// <summary>
-        /// QRCodeData
+        /// The QR code data used for rendering. Contains the module matrix that defines the QR code pattern.
         /// </summary>
         protected QRCodeData QrCodeData { get; set; }
 
         /// <summary>
-        /// AbstractQRCode
+        /// Initializes a new instance of the renderer and sets a process-wide regex timeout of 500ms.
         /// </summary>
         protected AbstractQRCode()
         {
@@ -27,9 +28,9 @@ protected AbstractQRCode()
         }
 
         /// <summary>
-        /// AbstractQRCode
+        /// Initializes a new instance of the renderer with the specified QR code data.
         /// </summary>
-        /// <param name="data"></param>
+        /// <param name="data">The <see cref="QRCodeData"/> generated by <see cref="QRCoder.Core.Generators.QRCodeGenerator"/>.</param>
         protected AbstractQRCode(QRCodeData data) : this()
         {
             this.QrCodeData = data;

QRCoder.Core/Assets/nuget-readme.md

@@ -1,42 +1,113 @@
-## About
+# QRCoder.Core
 
-QRCoder.Core is a simple library, written in C#.NET, based on [QrCode](https://github.com/codebude/QRCoder) which enables you to create QR codes. It is available as a .NET Core version on NuGet. It uses SkiaSharp for cross-platform compatibility.
+A cross-platform .NET library for QR Code generation using **SkiaSharp**. Compatible with **Windows**, **Linux**, **macOS**, and **mobile** (Xamarin / MAUI).
 
+Based on [QRCoder](https://github.com/codebude/QRCoder). Supports **.NET Standard 2.1**, **.NET 8.0**, **.NET 10.0**, and **.NET Framework 4.8**.
 
-***
+---
 
-## Documentation
+## Quick Start
 
-👉 *Your first place to go should be our wiki. Here you can find a detailed documentation of the QRCoder and its functions.*
-* [**QRCode Wiki**](https://github.com/codebude/QRCoder/wiki)  or [**QRCode.Core Wiki**](https://github.com/afonsoft/QRCoder.Core/wiki)
+```csharp
+using QRCoder.Core;
+
+// Generate QR code data
+using var generator = new QRCodeGenerator();
+using var data = generator.CreateQrCode("https://github.com/afonsoft/QRCoder.Core",
+    QRCodeGenerator.ECCLevel.M);
+
+// Render as PNG bytes (cross-platform, no System.Drawing needed)
+using var png = new PngByteQRCode(data);
+byte[] pngBytes = png.GetGraphic(10);
+File.WriteAllBytes("qrcode.png", pngBytes);
+```
+
+## Output Formats
 
-## Usage / Quick start
+| Format | Class | Example |
+|--------|-------|---------|
+| **PNG** | `PngByteQRCode` | `new PngByteQRCode(data).GetGraphic(10)` → `byte[]` |
+| **SVG** | `SvgQRCode` | `new SvgQRCode(data).GetGraphic(10)` → `string` |
+| **PDF** | `PdfByteQRCode` | `new PdfByteQRCode(data).GetGraphic(5)` → `byte[]` |
+| **ASCII** | `ASCIIQRCode` | `new ASCIIQRCode(data).GetGraphic(1)` → `string` |
+| **Base64** | `Base64QRCode` | `new Base64QRCode(data).GetGraphic(10)` → `string` |
+| **SKBitmap** | `QRCode` | `new QRCode(data).GetGraphic(10)` → `SKBitmap` |
+| **Postscript** | `PostscriptQRCode` | `new PostscriptQRCode(data).GetGraphic(5)` → `string` |
+| **Artistic** | `ArtQRCode` | `new ArtQRCode(data).GetGraphic(10)` → `SKBitmap` |
+| **BMP** | `BitmapByteQRCode` | `new BitmapByteQRCode(data).GetGraphic(10)` → `byte[]` |
 
-You only need four lines of code, to generate and view your first QR code.
+## Multiple Formats Example
 
 ```csharp
-using (QRCodeGenerator qrGenerator = new QRCodeGenerator())
-using (QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q))
-using (QRCode qrCode = new QRCode(qrCodeData))
-{
-    Bitmap qrCodeImage = qrCode.GetGraphic(20);
-}
+using QRCoder.Core;
+
+using var gen = new QRCodeGenerator();
+using var data = gen.CreateQrCode("Hello World", QRCodeGenerator.ECCLevel.M);
+
+// SVG
+using var svg = new SvgQRCode(data);
+string svgString = svg.GetGraphic(10);
+
+// ASCII (terminal)
+using var ascii = new ASCIIQRCode(data);
+Console.WriteLine(ascii.GetGraphic(1));
+
+// PDF
+using var pdf = new PdfByteQRCode(data);
+byte[] pdfBytes = pdf.GetGraphic(5);
+
+// With custom colors
+using var qr = new QRCode(data);
+using var bitmap = qr.GetGraphic(10, "#1a1a2e", "#e0e0e0");
 ```
 
-### Optional parameters and overloads
+## Payload Types
 
-The GetGraphics-method has some more overloads. The first two enable you to set the color of the QR code graphic. One uses Color-class-types, the other HTML hex color notation.
+Generate formatted QR code content for common use cases:
 
 ```csharp
-//Set color by using Color-class types
-Bitmap qrCodeImage = qrCode.GetGraphic(20, Color.DarkRed, Color.PaleGreen, true);
+using QRCoder.Core;
 
-//Set color by using HTML hex color notation
-Bitmap qrCodeImage = qrCode.GetGraphic(20, "#000ff0", "#0ff000");
+using var gen = new QRCodeGenerator();
+
+// Wi-Fi
+var wifi = new PayloadGenerator.WiFi("MyNetwork", "MyPassword",
+    PayloadGenerator.WiFi.Authentication.WPA);
+using var wifiData = gen.CreateQrCode(wifi.ToString(), QRCodeGenerator.ECCLevel.M);
+
+// URL
+var url = new PayloadGenerator.Url("https://github.com/afonsoft/QRCoder.Core");
+using var urlData = gen.CreateQrCode(url.ToString(), QRCodeGenerator.ECCLevel.M);
+
+// Email
+var mail = new PayloadGenerator.Mail("test@example.com", "Subject", "Body");
+using var mailData = gen.CreateQrCode(mail.ToString(), QRCodeGenerator.ECCLevel.M);
+
+// Phone Number
+var phone = new PayloadGenerator.PhoneNumber("+1234567890");
+using var phoneData = gen.CreateQrCode(phone.ToString(), QRCodeGenerator.ECCLevel.M);
+
+// Contact Card (vCard)
+var contact = new PayloadGenerator.ContactData(
+    PayloadGenerator.ContactData.ContactOutputType.VCard3,
+    "Doe", "John", phone: "+1234567890", email: "john@example.com");
+using var contactData = gen.CreateQrCode(contact.ToString(), QRCodeGenerator.ECCLevel.M);
 ```
 
-The other overload enables you to render a logo/image in the center of the QR code.
+Supported payloads: URL, WiFi, Mail, SMS, PhoneNumber, MMS, Geolocation, CalendarEvent, ContactData, Bitcoin, Girocode, BezahlCode, SwissQrCode, OneTimePassword, ShadowSocksConfig, Bookmark, SkypeCall, WhatsAppMessage, and more.
 
-```csharp
-Bitmap qrCodeImage = qrCode.GetGraphic(20, Color.Black, Color.White, (Bitmap)Bitmap.FromFile("C:\\myimage.png"));
-```
+## Error Correction Levels
+
+| Level | Recovery | Use Case |
+|-------|----------|----------|
+| `ECCLevel.L` | ~7% | Maximum data capacity |
+| `ECCLevel.M` | ~15% | General purpose (recommended) |
+| `ECCLevel.Q` | ~25% | Higher reliability |
+| `ECCLevel.H` | ~30% | Maximum recovery (logos, artistic QR) |
+
+## Documentation & Source
+
+- **Repository**: [https://github.com/afonsoft/QRCoder.Core](https://github.com/afonsoft/QRCoder.Core)
+- **Usage Guide**: [https://github.com/afonsoft/QRCoder.Core/blob/main/docs/en-US/usage-guide.md](https://github.com/afonsoft/QRCoder.Core/blob/main/docs/en-US/usage-guide.md)
+- **Issues**: [https://github.com/afonsoft/QRCoder.Core/issues](https://github.com/afonsoft/QRCoder.Core/issues)
+- **License**: MIT

QRCoder.Core/Exceptions/DataTooLongException.cs

@@ -3,7 +3,8 @@
 namespace QRCoder.Core.Exceptions
 {
     /// <summary>
-    /// DataTooLongException
+    /// Thrown when the input data exceeds the maximum capacity allowed by the QR code standard
+    /// for the specified error correction level, encoding mode, and optional fixed version.
     /// </summary>
     public class DataTooLongException : Exception
     {

QRCoder.Core/Extensions/SKColorExtensions.cs

@@ -3,13 +3,23 @@
 
 namespace QRCoder.Core.Extensions
 {
+    /// <summary>
+    /// Extension methods for converting <see cref="SKColor"/> values to and from hexadecimal string notation.
+    /// </summary>
     public static class SKColorExtensions
     {
+        /// <summary>
+        /// Converts this color to an ARGB hexadecimal string (e.g., "#FF000000" for opaque black).
+        /// </summary>
         public static string ToHex(this SKColor color)
         {
             return string.Format(CultureInfo.InvariantCulture, "#{0:X2}{1:X2}{2:X2}{3:X2}", color.Alpha, color.Red, color.Green, color.Blue);
         }
 
+        /// <summary>
+        /// Parses a hexadecimal color string (#RRGGBB or #AARRGGBB) into an <see cref="SKColor"/>.
+        /// Returns <see cref="SKColors.Transparent"/> for null, empty, or invalid input.
+        /// </summary>
         public static SKColor FromHex(string hex)
         {
             if (string.IsNullOrEmpty(hex))

QRCoder.Core/Extensions/StringValueAttribute.cs

@@ -10,7 +10,7 @@ public class StringValueAttribute : Attribute
         #region Properties
 
         /// <summary>
-        /// Holds the alue in an enum
+        /// Holds the string value associated with the enum member.
         /// </summary>
         public string StringValue { get; protected set; }
 
@@ -27,7 +27,7 @@ public StringValueAttribute(string value)
     }
 
     /// <summary>
-    /// CustomExtensions
+    /// Extension methods for retrieving <see cref="StringValueAttribute"/> values from enum members.
     /// </summary>
     public static class CustomExtensions
     {

QRCoder.Core/Models/QRCodeData.cs

@@ -6,12 +6,15 @@
 namespace QRCoder.Core.Models
 {
     /// <summary>
-    /// QRCodeData
+    /// Stores the encoded QR code data as a module matrix. Each element in the matrix represents
+    /// a row of modules (black/white squares). Generated by <see cref="QRCoder.Core.Generators.QRCodeGenerator"/>
+    /// and consumed by renderer classes to produce visual output.
     /// </summary>
     public class QRCodeData : IDisposable
     {
         /// <summary>
-        /// Module Matrix
+        /// The module matrix representing the QR code. Each <see cref="BitArray"/> is a row,
+        /// where true = dark module and false = light module.
         /// </summary>
         public List<BitArray> ModuleMatrix { get; set; }
 
@@ -25,20 +28,20 @@ public QRCodeData(int version)
         }
 
         /// <summary>
-        /// QRCodeData
+        /// Loads QR code data from a file in the proprietary QRR format.
         /// </summary>
-        /// <param name="pathToRawData">pathToRawData</param>
-        /// <param name="compressMode">compressMode</param>
+        /// <param name="pathToRawData">Path to the QRR file containing saved QR code data.</param>
+        /// <param name="compressMode">Compression mode used when the file was saved.</param>
         public QRCodeData(string pathToRawData, Compression compressMode) : this(File.ReadAllBytes(pathToRawData), compressMode)
         {
         }
 
         /// <summary>
-        /// QRCodeData
+        /// Loads QR code data from a byte array in the proprietary QRR format.
         /// </summary>
-        /// <param name="rawData">rawData</param>
-        /// <param name="compressMode">compressMode</param>
-        /// <exception cref="Exception">Exception</exception>
+        /// <param name="rawData">Byte array containing saved QR code data in QRR format.</param>
+        /// <param name="compressMode">Compression mode used when the data was saved.</param>
+        /// <exception cref="InvalidOperationException">Thrown when the raw data does not match the QRR file format.</exception>
         public QRCodeData(byte[] rawData, Compression compressMode)
         {
             var bytes = new List<byte>(rawData);
@@ -105,10 +108,11 @@ public QRCodeData(byte[] rawData, Compression compressMode)
         }
 
         /// <summary>
-        /// GetRawData
+        /// Serializes the QR code data into a byte array in the proprietary QRR format,
+        /// with optional Deflate or GZip compression.
         /// </summary>
-        /// <param name="compressMode">compressMode</param>
-        /// <returns></returns>
+        /// <param name="compressMode">The compression algorithm to apply to the output.</param>
+        /// <returns>A byte array containing the QR code data in QRR format.</returns>
         public byte[] GetRawData(Compression compressMode)
         {
             var bytes = new List<byte>();
@@ -172,10 +176,10 @@ public byte[] GetRawData(Compression compressMode)
         }
 
         /// <summary>
-        /// SaveRawData
+        /// Saves the QR code data to a file in the proprietary QRR format.
         /// </summary>
-        /// <param name="filePath">filePath</param>
-        /// <param name="compressMode">compressMode</param>
+        /// <param name="filePath">The path where the QRR file will be written.</param>
+        /// <param name="compressMode">The compression algorithm to apply.</param>
         public void SaveRawData(string filePath, Compression compressMode)
         {
             File.WriteAllBytes(filePath, GetRawData(compressMode));
@@ -216,7 +220,7 @@ protected virtual void Dispose(bool disposing)
         }
 
         /// <summary>
-        /// Compression
+        /// Specifies the compression algorithm used when saving or loading QR code data.
         /// </summary>
         public enum Compression
         {

QRCoder.Core/Models/Size.cs

@@ -1,8 +1,18 @@
 namespace QRCoder.Core.Models
 {
+    /// <summary>
+    /// Represents the dimensions (width and height) of a QR code rendering area.
+    /// </summary>
     public struct Size
     {
+        /// <summary>
+        /// The width of the rendering area in the target unit (pixels, points, etc.).
+        /// </summary>
         public double Width { get; set; }
+
+        /// <summary>
+        /// The height of the rendering area in the target unit (pixels, points, etc.).
+        /// </summary>
         public double Height { get; set; }
 
         public Size(double width, double height)

QRCoder.Core/Renderers/ArtQRCode.cs

@@ -10,7 +10,8 @@
 namespace QRCoder.Core.Renderers
 {
     /// <summary>
-    /// ArtQRCode
+    /// Renders a QR code with artistic styling using rounded dots instead of square modules.
+    /// Supports custom dot colors, background images, and quiet zone control.
     /// </summary>
     public class ArtQRCode : AbstractQRCode
     {

QRCoder.Core/Renderers/AsciiQRCode.cs

@@ -9,7 +9,8 @@
 namespace QRCoder.Core.Renderers
 {
     /// <summary>
-    /// AsciiQRCode
+    /// Renders a QR code as ASCII art text, suitable for terminal/console output.
+    /// Each module is represented by configurable dark and light character strings.
     /// </summary>
     public class AsciiQRCode : AbstractQRCode
     {

QRCoder.Core/Renderers/Base64QRCode.cs

@@ -12,7 +12,8 @@
 namespace QRCoder.Core.Renderers
 {
     /// <summary>
-    /// Base64QRCode
+    /// Renders a QR code as a Base64-encoded image string. Useful for embedding QR codes
+    /// directly in HTML img tags or CSS without requiring a separate file.
     /// </summary>
     public class Base64QRCode : AbstractQRCode
     {

QRCoder.Core/Renderers/BitmapByteQRCode.cs

@@ -9,7 +9,8 @@
 namespace QRCoder.Core.Renderers
 {
     /// <summary>
-    /// SKBitmapByteQRCode
+    /// Renders a QR code as a raw BMP (bitmap) byte array. Produces an uncompressed
+    /// 24-bit color bitmap image suitable for further processing or display.
     /// </summary>
     // ReSharper disable once InconsistentNaming
     public class SKBitmapByteQRCode : AbstractQRCode

QRCoder.Core/Renderers/PdfByteQRCode.cs

@@ -15,7 +15,8 @@
 namespace QRCoder.Core.Renderers
 {
     /// <summary>
-    /// PdfByteQRCode
+    /// Renders a QR code as a PDF document byte array. Generates a minimal valid PDF
+    /// containing the QR code image with configurable colors and quiet zone.
     /// </summary>
     // ReSharper disable once InconsistentNaming
     public class PdfByteQRCode : AbstractQRCode

QRCoder.Core/Renderers/PngByteQRCode.cs

@@ -9,7 +9,8 @@
 namespace QRCoder.Core.Renderers
 {
     /// <summary>
-    /// PngByteQRCode
+    /// Renders a QR code as a PNG image byte array. This renderer does not require System.Drawing
+    /// and works cross-platform on Windows, Linux, macOS, and mobile.
     /// </summary>
     public sealed class PngByteQRCode : AbstractQRCode
     {

QRCoder.Core/Renderers/PostscriptQRCode.cs

@@ -9,7 +9,8 @@
 namespace QRCoder.Core.Renderers
 {
     /// <summary>
-    /// PostscriptQRCode
+    /// Renders a QR code as a Postscript or EPS (Encapsulated PostScript) string.
+    /// Suitable for high-quality print output and vector graphics workflows.
     /// </summary>
     public class PostscriptQRCode : AbstractQRCode
     {