I don't know if I used the right board for this, but I was wondering how to I make a toggle spoiler button? I'm about to do a large hoard sale, and I have a lot of things. So I wanted to to put a spoiler button or whatever it is called on for each subject of items so that it's not a super long thing people need to scroll through just to see if I have what they want.

It'd be much appreciated if someone showed me/tells me how to do it!