Updated README for SASS/Compass.

[dbalatero]

Hey @mjbellantoni,

This updates the README to provide some instructions for getting running with SASS + Twitter Bootstrap (I tested on the Compass flavor).

Let me know if there's an easier way for me to do what I did in config/application.rb.

[mjbellantoni]

@dbalatero Hello David. Sorry I haven't gotten to this yet. I've just started a new job and I'm a little busy at the moment. I'll get to this in the next several days.

[dbalatero]

No problem.

[wulffeld]

Would be nice to have merged. Just wasted two hours :(

UPDATE: Actually I'm not even sure this is needed anymore. Was editing the wrong file here.