Goodies: Adding documentation for roles & helpers

Related to/depends on: 
* https://github.com/duckduckgo/zeroclickinfo-goodies/pull/576
* https://github.com/duckduckgo/duckduckgo/pull/91
I'm getting this in the docs:

![screen shot 2014-08-22 at 2 29 17 pm](https://cloud.githubusercontent.com/assets/81969/4015400/4ac950ac-2a2a-11e4-9999-60e5a003add4.png)

Maybe because there's this extra ticks. Very cool, though! https://duck.co/duckduckhack/goodie_helpers