Update docs for v2, and move them to version control

[Tim Wisniewski]

Some of the docs are outdated now, with v2's changes.

We should also move them to version control (e.g. a docs folder) to make it easier to ensure documentation stays up to date, and reflects the codebase. Some of it may be a bit odd to have exist in forks (e.g. how to deploy a JKAN instance), but that's probably okay.