Basic styles of documentation

* Style documentation nav links
* Move search bar to partial
* Reduce spacing in doc nav items
* Refactor individual doc files

![screen shot 2014-11-09 at 7 22 25 pm](https://cloud.githubusercontent.com/assets/3300569/4970721/d7f9dd1a-6888-11e4-926f-748888160229.png)

https://trello.com/c/7cYuLORT
Could you use updated syntax:

`class: "built-with-middleman-link"`