Grammar fixins

Here's a list of the grammar and spelling fixes I did on this commit. I'll send another if I find any more issues when I'm finished with the tutorial.

SP: Under "Checking Your Work: Troubleshooting." 
* "I would not suggest using these settings in a production ENVIRONMENT"

SP: Under "Getting Configged Up"
* "FIRST head over to…"

SP: Under "Every Building Needs a Scaffold"
* "you can see that THE controller, model, and view…"
* "…no table has been created. That's…"

GM: Under "Now that we have a comment…"
* "find the comment, based on ITS id"

SP/GM: Under "Number of comments"
* "…easier way to read it and it uses FUEL'S…"
* "A single comment displays "1 Comment…""
* "top of the function), and…"