Move development docs to a github wiki for easier access to all doc pages

[dae]

Manual / FAQ Wiki

Way back in Anki’s early days, the docs were on a wiki. I found it frustrating to deal with abuse and low-quality contributions. A wiki doesn’t remove the burden of review - changes still need to be checked, but the difference is that they’ve already gone through in the wiki case, so other work needs to be put on hold when a page defacement needs cleaning up. Note however that this forum does support marking a post as a wiki page, allowing others to edit it. And there have been some good long-f…