Add Grunt Support to Grunterie Child

This is an overhaul of the Grunterie Child Theme

Added Grunt support
Dropped config.rb since Compass is handled by Grunt
[Fixed stylesheet path in parent theme](https://github.com/gpspake/grunterie/commit/1ec7293648092ed949a0a6abde6572c239d6a8f1) to point to the correct location if the child theme is activated 
Updated Readme with install instructions and other info