minor doc UI fixes

before:
![ember js - ember instrumentation 2014-02-17 18-12-21 2014-02-17 18-12-26](https://f.cloud.github.com/assets/1131196/2190418/f7c2cbce-9828-11e3-8ec4-d31d305f1920.jpg)
after:
![ember js - ember instrumentation 2014-02-17 18-12-48 2014-02-17 18-12-52](https://f.cloud.github.com/assets/1131196/2190422/076d4e78-9829-11e3-8692-aecb97100b13.jpg)