Added TOC and added link to docs folder

Author: kizu

CONTRIBUTE.md

@@ -1,6 +1,10 @@
 # Contributing to CSSComb
 
-<a name="pull-requests"></a>
+## Table of Contents
+
+- [Pull requests](#pull-requests)
+- [For maintainers](#for-maintainers)
+
 ## Pull requests
 
 1. [Fork](http://help.github.com/fork-a-repo/) the project, clone your fork, and configure the remotes:
@@ -32,7 +36,7 @@ git checkout -b <topic-branch-name>
 4. Patches and features will not be accepted without tests.
    Run `npm test` to check that all tests pass after you've made changes.
 
-5. Update the `README.md` if there were corresponding changes or new options.
+5. Update the `README.md` or [docs](https://github.com/csscomb/csscomb.js/tree/master/doc) if there were corresponding changes or new options.
 
 6. Locally rebase the upstream development branch into your topic branch:
 
@@ -48,8 +52,7 @@ git push origin <topic-branch-name>
 
 8. [Open a Pull Request](https://help.github.com/articles/using-pull-requests/) to a `dev` branch with a clear title and description.
 
-<a name="maintainers"></a>
-## Maintainers
+## For maintainers
 
 ### Submitting changes