Update USERGUIDE.md
Update USERGUIDE.md

Update IRC commands with a new option, `!`.

noraesae/koko,hachibasu/koko,KokoIRC/koko,noraesae/koko,alienxp03/koko,alienxp03/koko,noraesae/koko,alienxp03/koko,woss/koko,hachibasu/koko,woss/koko,woss/koko,KokoIRC/koko,KokoIRC/koko,hachibasu/koko