* Link ZipFile in What's New entry discussing it

* Add entry for new ZipFile.mkdir method

* Add entry for new zipfile.Path.stem/suffix/suffixes methods

* Add missing line breaks between zipfile bullet list items
(cherry picked from commit ed827d56)

Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>