more helpful error message around `ValueError: invalid modifier key: 'command'`

[dwiel]

I got the following error message: ValueError: invalid modifier key: 'command'. Something like ValueError: invalid modifier key: 'command' did you mean 'cmd'? would have saved me from having to look around for what i was supposed to us. Probably most helpful for new users.

[lunixbochs]

ValueError: Invalid modifier key: 'command'. Try one of these: cmd, win, super, ctrl, shift, alt, fn