(Maybe that’s what the ? Button in the button left will do, but it doesn’t at the moment)
For styles like bold and italics it’s more clear the syntax after you use it, but for things like making it a quote level (>) it never actually shows you.
this could be indeed a useful feature, and you were right - this is the planned functionality of the (?) button; we are still playing with it on design level and, because it is not breaking, we have not yet implemented it in alpha.
We would love to display the list of the supported markdown syntax in Bear; it could help users to get used to the syntax and become markdown masters!