Request: Channel grouping.

[Wolfie713]

As discussed on Discord, here's an example 'config' setup.

groups=[
	{
		# group name, for labeling purposes only.
		group-name="main channel"

		# channels.  channel-id = numerical ID of the discord channel
		# direction=in (doesn't send out), out (doesn't accept messages), both
		channels {
			{
				channel-id="12345"
				prefix="[SRV1]"
				direction=BOTH
			},
			{
				channel-id="54321"
				username-format="[SRV2] message from %author_displayname%"
				direction=BOTH
			},
			{
				channel-id="67890"
				prefix="[SRV3]"
				direction=BOTH
			}
		}

		# username-format can be customized per channel instead of just the prefix.
		username-format="%prefix% %author_displayname%"

		# prefix is the default used
		prefix="[DisLink]"
	}
]