Who needs documentation if we have Stack Overflow? /s
Seriously, I had to learn React for my new job (not a web dev by trade), and while I don't dislike the framework (a compliment in programming land), a lot of times I had to resort to Stack Overflow for information that should have been provided by the documentation; which instead assumed I already understood how React worked, or forgot to mention that things were different in ES6, or mentioned that things were different but wasn't clear about how.
The worst part is that when I complained about this to my friends they said "oh, React is one of the better documented frameworks out there". At that point I honestly wondered how has any webdeveloper has managed to stay sane during the last decade.
As for fun coding with good documentation, I suggest Processing:
.. good luck using that professionally though, unless you get paid for creating interactive art.