What do you like about it? It wasn't immediately obvious to me that those were even clickable and the <details> text does not differ from the <summary> text so it all kind of rolls together in a weird way as your click around.
I think they mean the unexpected usage of semantic markup in the wild. It's an ongoing battle to get it used more broadly, so it's nice to see it popping up unannounced and working so nicely. Your (valid) gripes are mostly out of the repo's control, as all styling appears to be GitHub.
