Set Karuta Prefix

Change the Karuta prefix Leg listens to.

Command: "leg karutaprefix [Prefix]"

This prefix is what Leg listens to in order to identify commands targeted at Karuta.

This is mainly used for Cached Lookups and other features that intercept Karuta commands.

Leg only listens to one prefix at a time. For example: If you set this to "k!", Leg won't respond when someone does "klu"