Nice! I missed it (or it didn't exist) when I last looked at Clojure a few years back

You missed it, it has been there forever. But it says good and bad things about Clojure that its reference documentation is one of its weakest points.

The Guide/Reference split obscures a lot of information (do I want guidance on Deps & CLI or do I want reference on Deps & CLI?) and the guides where that gem is hidden randomly mix advanced topics (eg, how to set up generative testing), beginner topics (how to read Clojure code) and library author topics (eg, Reader Conditionals).

When you think about it, there is nearly no trigger to look at the guides when the information you need is there. Clojure is a weird mix of both well documented and terribly documented. All the facts are on the website, very few of them are accessible when required. The people who make it past that gauntlet are rewarded by getting to use Clojure.

In my case it was even worse, as I started with ClojureScript, and official documentation was simply abysmal then.