[DOC beta] Several doc fixes

Before:

![ember js - ember run 2013-12-26 16-11-45](https://f.cloud.github.com/assets/1131196/1812228/53e59804-6e72-11e3-82a4-85d02320785f.jpg)

After:

![ember js - ember run 2013-12-26 16-12-03](https://f.cloud.github.com/assets/1131196/1812229/5ecb6334-6e72-11e3-9106-5ef43dedb76d.jpg)