Improve the commented suggested "better" auto-generated schema

[AndydeCleyre]

Here's a good example of where it fails to match properly: KenKundert/nestedtext#40 (comment)

[AndydeCleyre]

The feature/experimental-schema-guessing branch now succeeds with the above example. But I will need to do a lot more testing to make sure it never produces worse results than the current method. And I've left a cry for help in the yamlpath discussions.

[AndydeCleyre]

A general note: I haven't worked on that in a while. I paused because in order to "properly" improve the guessing, it seemed that I would need to hold on to more of the original data for longer, and I'm not sure the extra complexity is worthwhile. If this issue matters to you, please add a reaction or comment here to help me gauge demand. Thanks!