Move the TODOs and WebSocket messages to the wiki.

The wiki should contain the developer documentation, not the single README page.
Update the README description.

Add a slightly longer description.
Make user press a button to change name.

Fixes a TODO that Caleb brought up.
Change 'others' to 'spectators'

Fixes TODO gleaned from Onkur that 'others' was confusing.
Players can now switch between roles.

Make the list of players, including empty players, visible and
highlightable so that you can see which is your role.
Add divs that show the current player turn.

These are probably very confusing because they don't correspond with the
usernames and don't take into account a finished or unstarted game.