docs: Minor grammar fixes. Input needed on other proposed enhancements.

I was lying in bed with a cold today and decided to do some doc cleanup.

There are a few other changes I would like to make but would like some input first:

1. The Unit Testing section of the guide is incomplete. I would be happy to finish it off if whoever wrote the original doc could give me a few lines of what they intended to cover under each incomplete heading.
2. The tutorial is using an older version of the seed project. What about updating it to use yeoman or at least Testacular? Not sure if that would make it harder for Windows users, though.
3. The tutorial is also using the "global function" style. What about updating it to use myApp.controller() as that seems to be a best practice?