New port: irc/bitlbee-discord

Bitlbee plugin to allow connections to the discord chat service.
A more lightweight alternative to using bitlbee compiled with
libpurple support.

WWW: https://github.com/sm00th/bitlbee-discord

PR: 234007
Submitted by: Arthur Pirika <arfy32@gmail.com>
Reviewed by: koobs, ndowens@yahoo.com