Foreman 1.10 manual

I've copied the Foreman 1.9 manual to 1.10 so we can begin preparing
documentation updates for the upcoming release.

Please look at the TODO list here and see if you can help. The updates
cover all sorts of areas of the web UI, smart proxy and more:

Just open up PRs to this repository targeting _includes/manuals/1.10/,
no tickets required.

I'd suggest leaving the itemised release notes and contributors lists
until we get closer to release.

ยทยทยท -- Dominic Cleal