Use MineDown library for chat formatting

[lokka30]

A user requested in the Reviews section on SpigotMC to add support for legacy colour codes (&a, &b, &c, etc).

MineDown is a library I've historically had success with in adding this; it's also great since it supports the existing MiniMessage syntax so there is zero compatibility issue with existing installations.

However, I'm rather skeptical on adding in more libraries/dependencies for the plugin, as any additional libraries we depend on is an extra possibility that BlackWidow will be slower to update for Minecraft versions, or may have to drop features if the said dependency doesn't update.

I'll jot this down as won't fix for now, but will leave this issue active whilst it is still something that can be considered.

Feel free to discuss below.