Adding command to archive adventure clubs

[maxcell]

There may be more here to this but we'd like to eventually find ways to wind them down. It was discussed to not to delete them. This allows us to archive them for folks to capture conversations and knowledge.

It would be fine to delete the role associated with that channel and potentially spin up an alumni adventure-club role. This would be a way to distinguish folks who have gone through an adventure club so we can have them as spokespeople for how they've operated.