Add configurable commands

[TropicalShadow]

Allow for the Minecraft and Discord commands to be configured, to avoid conflicting naming.

New Config Location Options.CommandOverride

  CommandOverride:
    Discord:
      playerinfo: [ "playerinfo", "pi" ]
      verify: [ "verify" ]
    Minecraft:
      verify: ["verify"]
      staff: ["staff", "s"]
      dchat: ["dchat"]

First value in the config is the Default Command name, the rest are consider aliases

[TropicalShadow]

Feature for #23