Update .cocoadocs.yml

The CSS that is generated from the yaml file dies on the fonts, I wonder if there was a copy & paste error?

So I've removed the font section as that wasn't being used.
![screen shot 2014-07-30 at 09 58 25](https://cloud.githubusercontent.com/assets/49038/3746940/c738249e-17c7-11e4-9bfc-3e1bc21ebd2c.png)