README restructure

* Make instructions more clear and succinct
* Better align with Bourbon README
* Use double prime marks in examples, per our guides
* Provide numbered instructions

In the future, I would like to tweak and bring clarity to the “Using Neat” section.

I’m also curious if the FAQ’s section would be better served as a Wiki page; thoughts?
We have yet to create this page. We'd rather do that before merging this or remove this line until we do.