Sorry if asked/answered before.
Tried searching for: undefined, invalid, unspecified command_name syntax.
I would like for nightbot to respond when a user tries to use a command that is not an enabled default command, or a custom command.
So, !--whatever--, !sdfkljhgd, !thisIsNotACommand etc (provided they are not custom commands).
The response would be very similar to the regular !commands, maybe with 1 additional link and a short message.