Add sources info for fonts

Author: camdecoster

.github/fonts/SOURCES.md

@@ -0,0 +1,14 @@
+# Font Sources
+
+These fonts were downloaded from Google Fonts and related repositories for use in image baseline generation during CI. They ensure consistent text rendering across environments.
+
+They can be re-downloaded using the script at `.github/scripts/download_google_fonts.py`.
+
+- **NotoSansMono** (Regular, Bold) — [notofonts/notofonts.github.io](https://cdn.jsdelivr.net/gh/notofonts/notofonts.github.io/fonts/NotoSansMono/hinted/ttf/)
+- **NotoSans** (Regular, Italic, Bold) — [notofonts/notofonts.github.io](https://cdn.jsdelivr.net/gh/notofonts/notofonts.github.io/fonts/NotoSans/hinted/ttf/)
+- **NotoSerif** (Regular, Italic, Bold, BoldItalic) — [notofonts/notofonts.github.io](https://cdn.jsdelivr.net/gh/notofonts/notofonts.github.io/fonts/NotoSerif/hinted/ttf/)
+- **OldStandard** (Regular, Italic, Bold) — [google/fonts](https://raw.githubusercontent.com/google/fonts/refs/heads/main/ofl/oldstandardtt/)
+- **PT Sans Narrow** (Regular, Bold) — [google/fonts](https://raw.githubusercontent.com/google/fonts/refs/heads/main/ofl/ptsansnarrow/)
+- **Raleway** (Regular, Regular-Italic, Bold, Bold-Italic) — [impallari/Raleway](https://raw.githubusercontent.com/impallari/Raleway/refs/heads/master/fonts/v3.000%20Fontlab/TTF/)
+- **Roboto** (Regular, Italic, Bold, BoldItalic) — [googlefonts/roboto-2](https://raw.githubusercontent.com/googlefonts/roboto-2/refs/heads/main/src/hinted/)
+- **GravitasOne** (400Regular) — [expo/google-fonts](https://raw.githubusercontent.com/expo/google-fonts/refs/heads/main/font-packages/gravitas-one/400Regular/)