Rename docs into full form

Author: przemyslawzalewski

README.md

@@ -3,7 +3,7 @@
 [![Greenkeeper badge](https://badges.greenkeeper.io/sandstreamdev/std.svg)](https://greenkeeper.io/)
 [![All Contributors](https://img.shields.io/badge/all_contributors-4-orange.svg?style=flat-square)](#contributors)
 
-## Docs
+## Documentation
 
 <!-- DOCS:START - Do not remove or modify this section -->