docs(#2934): index contributing

Author: alex-courtis

CONTRIBUTING.md

@@ -18,9 +18,8 @@ markdown-toc --maxdepth=2 -i CONTRIBUTING.md
   * [check](#check)
 - [Diagnostics](#diagnostics)
 - [Backwards Compatibility](#backwards-compatibility)
-- [Adding New Actions](#adding-new-actions)
 - [Documentation](#documentation)
-  * [Opts](#opts)
+  * [Config And Mappings](#config-and-mappings)
   * [API](#api)
 - [Windows](#windows)
 - [Pull Request](#pull-request)