Document the stylus settings

[balupton]

We currently use the following settings:

compress: true
'include css': true

This was added long ago, and trying to find out what other settings are available or what those settings do, is near impossible with the current documentation.

This is all the documentation there is on settings: http://learnboost.github.io/stylus/docs/js.html#setsetting-value

[ghost]

I guess the relatively new docs also don't help. -> http://stylus-lang.com/docs/js.html