[DOCS] Add complete listing of all possible settings & keybindings?

[rlue]

Per my comment in #361, it would make configuration much easier (and would be in the spirit of vim) to have some authoritative, comprehensive documentation of all possible settings and key bindings in Vim-Vixen.

Thanks, btw — I use it every day!

[AlexeySachkov]

@rlue, you may join me on working on this in #418

[rlue]

Great work man! This is a huge step forward.

Looks like it's already been merged, but I'll find some time this weekend to give it a once-over for style, grammar, and formatting.

I'm going to keep this issue open in the hopes that we may get an internal documentation system (like vim's) one day -- that is, one where you can type :h :bdeletes and get a quick description of what it does, without having to visit GH.

[rlue]

On second thought, @ueokande, could you enable the wiki for this repo? I think it would be easier to understand and navigate the documentation if mappings, commands, and properties could all go on separate pages (instead of all in one long README).

[victorz]

Still no wiki? :-( I would really appreciate a comprehensive listing of all the commands that I could use to bind keys to without scouring the source code to figure it out. <3