Create YouTube video tutorials for each command

We should make short (1 to 2 minute) video tutorials for each command, then make a playlist of these and put them somewhere (everywhere? in the README, on the server, as part of the welcome message, etc?)

Start by inventorying the bot's commands and estimating the number of tutorials required. Clarify where the playlist and individual videos should be published, then create a short tutorial for each command and verify that the agreed README, server, or welcome-message links are complete.

Written by the indexing model from the issue text.