[discussion] -> dev env with rainforest

Open to discussion around this. 

* If those aliases work, should we advise to use the bundler local deps?
* As it's making the submodules should we give advice on the fork & PR process given that you have to add your own as a remote?

#25 
More commas'd be cool:

> However, for someone new to high-level library development in ruby, this comes with a high learning curve.