Merge pull request #56 from GBH/patch-1

Fixing API link and adding button to rubygems

README.md

 MimeMagic is a library to detect the mime type of a file by extension or by content. It uses the mime database
 provided by freedesktop.org (see http://freedesktop.org/wiki/Software/shared-mime-info/).
 
+[![Gem Version](https://img.shields.io/gem/v/mimemagic.svg)](http://rubygems.org/gems/mimemagic)
+[![Gem Downloads](https://img.shields.io/gem/dt/mimemagic.svg)](http://rubygems.org/gems/mimemagic)
 [![Build Status](https://secure.travis-ci.org/minad/mimemagic.png?branch=master)](http://travis-ci.org/minad/mimemagic) [![Code Climate](https://codeclimate.com/github/minad/mimemagic.png)](https://codeclimate.com/github/minad/mimemagic)
 [![Gittip donate button](http://img.shields.io/gittip/bevry.png)](https://www.gittip.com/min4d/ "Donate weekly to this project using Gittip")
 [![Flattr this git repo](http://api.flattr.com/button/flattr-badge-large.png)](https://flattr.com/submit/auto?user_id=min4d&url=https://github.com/minad/mimemagic&title=MimeMagic&language=&tags=github&category=software)
@@ -29,7 +31,7 @@ You can add your own magic with `MimeMagic.add`. See `lib/mimemagic/overlay.rb`.
 API
 ===
 
-http://rdoc.info/github/minad/mimemagic/frames/file/README.md
+http://www.rubydoc.info/github/minad/mimemagic
 
 Tests
 =====