Add Contribute Link

README.md

@@ -1,8 +1,8 @@
 ### Calamares: Distribution-Independent Installer Framework
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-| [![Build Status](http://calamares.io/ci/buildStatus/icon?job=calamares-master)](http://calamares.pangea.pub/ci/job/calamares-master/) | [Report a Bug](http://calamares.io/bugs/) | Freenode (IRC): #calamares |
-|:-----------------------------------------:|:--------------------------:|:--------------------------:|
+| [![Build Status](http://calamares.io/ci/buildStatus/icon?job=calamares-master)](http://calamares.pangea.pub/ci/job/calamares-master/) | [Report a Bug](http://calamares.io/bugs/) | [Contribute](https://github.com/calamares/calamares/blob/master/HACKING.md) | Freenode (IRC): #calamares |
+|:-----------------------------------------:|:--------------------------:|:--------------------------:|:--------------------------:|
 
 ### Dependencies
 | Main | Partitioning Module |