Update readme to include development starting instructions

So I added a "getting started developing" cause I was GONNA write some tests for dis code where I found some coverage gaps, but then after I did the first two steps that I assumed, and I can't run the tests cause I get:

Running "jasmine:test" (jasmine) task
Warning: Arguments to path.join must be strings Used --force, continuing.

Sup with that.

grunt-cli v0.1.13
grunt v0.4.5
node v0.10.28