`joke`: Tell a joke.

    **Usage::**
        `joke` by itself: Tell a random joke
        `joke list`: Show all server-specific jokes
        `joke add [joke]`: Add server-specific joke
        `joke remove [id]`: Remove server-specific joke with its ID

    You must have the Manage Messages permission to add, remove, or look at the
    list of guild-specific jokes.

    When adding a joke, there are three "tokens" that are special:
        `$author` or `${author}`: The name of the person requesting a joke
        `$server` or `${server}`: The name of the server.
        `$channel` or `${channel}`: The name of the channel.

    When removing a joke, use the joke's ID from `joke list`.