Add docs badge to README

Author: rrrene

README.md

@@ -1,8 +1,10 @@
-# redis-rb [![Build Status][travis-image]][travis-link]
+# redis-rb [![Build Status][travis-image]][travis-link] [![Inline docs][inchpages-image]][inchpages-link]
 
 [travis-image]: https://secure.travis-ci.org/redis/redis-rb.png?branch=master
 [travis-link]: http://travis-ci.org/redis/redis-rb
 [travis-home]: http://travis-ci.org/
+[inchpages-image]: http://inch-pages.github.io/github/redis/redis-rb.png
+[inchpages-link]: http://inch-pages.github.io/github/redis/redis-rb
 
 A Ruby client library for [Redis][redis-home].