PEP 813 - The Pretty Print Protocol (round 2)

At the recently concluded Python core team sprint, @ericvsmith and I worked on some major updates to PEP 813 - The Pretty Print Protocol. We think it’s in pretty[1] good shape and essentially ready to be proposed for Python 3.16. It was a lot of fun clanking away at a collaboration between the two of us, with Eric driving the updated reference implementation and me on the PEP. Here thusly is the round 2 discussion. Please continue the discussions here; I will ask the moderators to lock the r...