Added UI for configurability!!

Now a floating draggable div allows you to activate saltybot with
different parameters. Including 3 strategies (highest win rate, lowest
win rate, and random). You can set an all in threshold (a value that if
you are under, you will all in). Also there's an income modifier option
which lets you add to your bet a factor of your current balance.
Also, there's a safebet amount setting for what to bet when stats are
unavailable or the characters have no stats.

Still to come, win rate modifier on bets. Validation on the form. Better
styling (maybe) and more.