General grammar and style fixes in the book

Contains numerous grammar, style and readability fixes (see diff)

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | >= 2.3
| Fixed tickets | 
I think the new one sounds a bit awkward, but this might be better than both:

>
You now have a setup that will allow you to reuse the layout.

The word methodology (I almost definitely wrote that) seems a bit unnecessarily "boring" and technical :).