typing the command character brings up a list of valid commands

[rorysaur]

typing the command character, without pressing enter, shows a list of valid commands, with a 1-line description or usage example. this list can be in a sidebar or an overlay. the list stays up as long as the command character is the only character in the input. it goes away if the input is cleared.

optional: make the commands list an autocomplete-- it gets filtered by continued input.
optional: if the command is "set", show a new list of valid things you can set, with description for each.