Clojure has very good docs, but have in mind that they also expect some preliminary familiarity with functional programming, and maybe a basic understanding of LISP in general. Still, their docs are usually very good.

Lua docs are also pretty good, with good reference, albeit a bit wordy and verbosive for my taste – but it helps facilitate understanding for more novice programmers which is something that must be encouraged.

Apart from Elixir, Clojure and Lua, very few languages have such excellent docs like Rust. Rust is very complex and very big but they have docs and even free books with tons of exercises so you can become a master, if you can spare the time and energy.

Forgot to mention.

In the family of LISP languages, Racket is extremely beginner-friendly, definitely check it out.

I think Elm deserves to be mentioned here as well. While it is only for the front-end, it is well documented with a special focus to avoid relying on preliminary knowledge, and therefore is really nice for beginners.

I think it can offer an interesting entry point to functional programming, and programming in general (not many advanced concepts to learn).