Add grunt to STARTERKIT

Hi,

I really like the way Grunt works for compiling and watching folders. So, I created a patch that adds the nesesarry files to the starterkit.

If you haven't used Grunt before, be sure to check out the Getting Started guide, as it explains how to create a Gruntfile as well as install and use Grunt plugins.

The setup I use will only compile scss with compass using the settings in config.rb and watch the folder for use with livereload.