Adding supported languages to the README.

README

@@ -62,3 +62,29 @@ file extension of the filename provided as its first argument. If it
 still can't figure out what language it uses it will not syntax
 highlight and instead output plain HTML.
 
+Supported Languages
+============================
+
+The supported languages depends solely on the languages the 'colorize'
+egg supports. That list can be found here
+<http://wiki.call-cc.org/eggref/4/colorize>
+
+As of the latest update of the highlight library these languages are
+supported:
+
+  * Basic Lisp
+  * Scheme
+  * Emacs Lisp
+  * Lisp
+  * C
+  * C++
+  * Java
+  * C
+  * Erlang
+  * Python
+  * Ruby
+  * Haskell
+  * Unified Context Diff
+  * Cascading Style Sheets (CSS)
+  * Extensible Markup Language (XML)
+  * (Extensible) HyperText Markup Language ((X)HTML)