Added a link to docs.github.com

Author: wi5nia

README.md

@@ -1,6 +1,6 @@
 ## GitHub Docs <!-- omit in toc -->
 
-This repository contains the documentation website code and Markdown source files for docs.github.com.
+This repository contains the documentation website code and Markdown source files for [docs.github.com](docs.github.com).
 
 GitHub's Docs team works on pre-production content in a private repo that regularly syncs with this public repo.