The readme's good (could use some tweaking/trimming as you note). The jam rules request that submissions have clear instructions and dependencies on the game's Itch page. We're not policing that super hard this year, but since that's stated as a requirement, it's likely to be the first place that people go looking.
No need to apologise about the bumpy ride! In my eyes, an opportunity to learn about and practice packaging is a key part of what the jam offers. I figure it's better to discover and pass those hurdles on a jam project with peers and mentors around who can offer advice/experience than to have those hurdles be a surprise on something bigger/more serious down the track.