I’ve hacked my instruments.xml file in order to have a 1-line non-percussion staff. In Setup, add a concert pitch single staff instrument, duplicate it, then add the 1-line non-percussion staff and move it so it’s between the staves. (That’s if you need the bottom image at the link you posted, otherwise a normal 1-line percussion staff is fine.) Bracket the 3 staves. Create a layout for the 3 staves together and you should be able to do it.
