major rewrite of about.rst

Try to split it into two major sections, one user-focused, one more technical. User-focused on top, technical below. Really, this should just be two pages, the user-focused one much more prominent with a small link to the technical one, which can be a bit harder to find.
drop a redundant sentence
LINK ALL THE THINGS
LINKIFY ALL THE THINGS MORE
okay, okay, these are the last two links, I promise
Merge pull request #184 from AdamWill/feature/faq

Feature/faq