feature request: Chatter opt-in for bomb

In the base game there's a traveler that comes into the booth, places a bomb on the desk, and leaves. The player has to defuse the bomb

It would be great to allow chatters to type `!bomb` and `!nobomb` to opt in or out of this, and if a random attack chance happens, and the user has their bomb preference set to true, they leave or have a bomb