For jam games with Spectrum ports, I'm guessing that (a) you just include the ported versions as downloads on the Itch page and (b) you just zip up the 'RELEASE' folder in the relevant DAAD folder in order to provide everything needed for a user to play the game. Correct me if I'm wrong!
I note the 'RELEASE' folder includes a readme - does anyone have any advice about what to put in this file? I've not written one before.