Improve readme copy/paste + update URLs to HTTPS

- Make it easier to copy/paste the readme commands by using code blocks
- Update a few URLs to HTTPS to avoid redirects

Signed-off-by: Tim Smith <tsmith84@gmail.com>

Author: tas50

README.md

@@ -22,11 +22,15 @@ gem 'cgi'
 
 And then execute:
 
-    $ bundle
+```bash
+bundle
+```
 
 Or install it yourself as:
 
-    $ gem install cgi
+```bash
+gem install cgi
+```
 
 ## Usage
 
@@ -73,7 +77,6 @@ db.transaction do
 end
 ```
 
-
 ### Restore form values from file
 
 ```ruby

lib/cgi.rb

@@ -26,7 +26,7 @@
 # The file CGI::Session provides session management functionality; see that
 # class for more details.
 #
-# See http://www.w3.org/CGI/ for more information on the CGI protocol.
+# See https://www.w3.org/CGI/ for more information on the CGI protocol.
 #
 # == Introduction
 #

lib/cgi/core.rb

@@ -481,7 +481,7 @@ def params=(hash)
 
     ##
     # Parses multipart form elements according to
-    #   http://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.2
+    #   https://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.2
     #
     # Returns a hash of multipart form parameters with bodies of type StringIO or
     # Tempfile depending on whether the multipart form element exceeds 10 KB