I don't know who's really in charge of the docs. I suppose the PEP authors
are, collectively, but that runs the risk that we're all expecting the
person to our left in the circle to do it.

Would people be okay if I added the tutorial from Appendix A of PEP 636 to
Doc/whatsnew/3.10.rst? It's a bit shy of 200 lines, which is bigger than
the largest section there currently ("Parenthesized Context Managers" is
about 50 lines) but feels not unreasonable for something that's been the
subject of at least 7 PEPs and reviewed by two consecutive Steering
Councils. :-) The full whatsnew.rst is currently around 1000 lines. FWIW
the longest what's new ever was for 2.7, at 3300 lines. 3.8 was 2200 lines.

Okay, I'll just add the PR and we can take it from there.