Discord relay bot

[UnknownShadow200]

• [x] Handle http 429 error
• [x] Back off to avoid rate limiting
• [x] Recover from websocket dropout
• [x] Escape * ` etc from in-game chat
• [ ] Handle other errors (e.g. wrong authorisation token)
• [x] Add documentation page to wiki for instructions
• [x] Add ability to ignore certain discord user IDs should probably make this part of RelayBot so extensible to IRC too
• [ ] ~~Support pinging usernames (harder and will be done in phase 2)~~
• [x] Properly handle DM channels (no need for .x there)
• [ ] Fix losing a few messages when websocket reconnects
• [x] Allowing replacing certain words from in-game to discord
• [ ] More customisation https://cdn.discordapp.com/attachments/778711150724513853/845259657539092531/unknown.png

[rdebath]

Also

• [ ] Add "/ignore discord dumbDiscordUser"