New Look! Same Great Git-it

This updates the format of Git-it. Challenge instructions now move into a new html guide, which ships with the module and can be run via server or by copy-and-paste via the app.

Super excited about this :blue_heart: 

![screen shot 2014-07-09 at 9 45 19 pm](https://cloud.githubusercontent.com/assets/1305617/3534672/e9021f9a-07ef-11e4-8019-419fe753a2ee.png)
![screen shot 2014-07-09 at 9 45 26 pm](https://cloud.githubusercontent.com/assets/1305617/3534673/ea6e69c4-07ef-11e4-96ca-9b588b7e2ed1.png)
![screen shot 2014-07-09 at 9 43 18 pm](https://cloud.githubusercontent.com/assets/1305617/3534686/15e3e782-07f0-11e4-923e-f0efaec19b24.png)
![git-it-new-ss](https://cloud.githubusercontent.com/assets/1305617/3534687/1822a29a-07f0-11e4-8846-8e0ff120341b.png)