Make a command to un-set-up the automated conversations in a particular channel.

[JnBrymn]

Right now we run /penny set-topic to create a topic channel that allows members to sign up for automated chats.

Create a /penny un-set-topic to do the opposite.

Also make sure that the instructions about unsetting the topic channel are posted whenever the signup request is posted in each topic channel every 2 weeks.

Also, it might be time to change the name from /penny set-topic to something else. Maybe /penny introductions on and /penny introductions off?