Further improve !help #181
Description
We could still utilize the command parameter descriptions to provide a more detailed help for each command. Due to space constraints, this will not fit into the normal !help menu. But we could have an optional parameter to display a detailed help menu for the specified command, e.g., !help purge user. This would be especially helpful for text-only commands, since there is currently no way for a user to ever see the detailed parameter descriptions that are actually there in the code.
We might also want to in the addressed in 000d7fc!help menu differentiate the commands that are available as slash commands from the commands that are only available as text commands, e.g., by starting them with / instead of !.