GitHub projects trend on HN because a GitHub page is certainly not ‘just’ a ReadMe and a list of files, any more than a programming book is a just pile of paper and ink.
GitHub is one of the most valuable troves of information we have on the entire Internet, certainly - and represents countless hours of work from millions of people all over the world, openly contributing and sharing knowledge and tools with others, without the interest of profit.
I don’t think there are many other websites in the world that align with HN’s values more than GitHub. It’s almost invaluable to humanity.