Typos and readability suggestions

[jgoodrick]

Thanks so much for this library! And thank you for great documentation! I sat down this evening and enjoyed what I was reading so much that I figured I might as well take a moment to help improve the guide, especially since a pair of fresh eyes are the best way to find little typos and such. Feel free to revert any of my suggestions, as I know some of them might be considered just an English style choice.

[malcommac]

Thank you so much; that's an outstanding contribution to our doc!