PEP 784: Adding Zstandard to the standard library

[steve.dower]

@emmatyping

I think allowing for setting a pledged size is a reasonable feature request (which unfortunately can only go into 3.15 now).

I’d vote for this to go into 3.14. It’s far less inconvenient to have a difference between 3.14.0b2->b3 than it is to have a difference permanently between 3.14->3.15.

@hugovk can give official permission.