add /random and /flip chat commands

Very easily explained:

/random:
able to type for example "/random 1 999" and the mesaage posted will look like this: "/random 1 999: 394" (But the number should be highlighted in a way you can't highlight other things to make sure it's real)

/flip:
able to type "/flip" and the mesaage posted will look like this: "/flip: tails" (But the result should be highlighted in a way you can't highlight other things to make sure it's real)

Me and my friends really had a lot of fun deciding stuff based on these commands (but we used it in the steam chat, because steam already has these commands)