Add missing bindings up to 4.6 (core profile)

Closes #3

Author: hazeycode

README.md

@@ -3,7 +3,7 @@
 OpenGL loader interface, bindings and optional type-safe wrapper for Zig.
 
 Supports:
-  * OpenGL Core Profile up to version 4.3
+  * OpenGL Core Profile up to version 4.6
   * OpenGL ES up to version 2.0
 
 ## Getting started