Emacs Docs: The modern documentation website Emacs deserves

"This is just the info pages but rendered to a docusaurus site" <- pretty much!

"What does it provide over the upstream info HTML pages or just M-x info?":

Couple very small features I appreciate:

1. There is mega fast text search (tool bar at the upper right or press Cmd-K)
2. There is a Table of Contents in the sidebar, which I really like as it helps me see where in the manual I am. I'm weird as I consume most manuals as a reference rather than trying to internalize the entire tome. The weirdness is that I actually memorize (or try to memorize) the index of any manual / technical book I read. The heads up display of where exactly I am in the Table of Contents helps me understand where in the broader structure of the documentation I'm reading, which I find really informative. You don't get this with the plain HTML files.

A meta feature: I'm really interested in getting more people into Emacs as I'm really passionate about it. One of the biggest turn-offs I hear from folks is that Emacs is arcane or old news. The info manual and raw-ish HTML manual can be daunting for new users (I personally love the Info manual as it's easy to navigate and interactive; I dislike the HTML manual as it lacks Info's navigation features). This modern rendering of Emacs's docs is a vote against this common complaint, so I like that it can be more inviting to beginners or people who are considering adopting Emacs over something with more shine like VSCode.

I also stumbled across this, which is newer, and considerably more feature-ful, but the one in the original post is the sweet spot for me. https://doc.emacsen.de

See reddit announcement for author's commentary on features and discussion: https://www.reddit.com/r/emacs/comments/1qds62d/ann_emacs_docs_an_emacs_documentation_website/