bpo-37759:  First round of major edits to Whatsnew 3.8 (GH-15127) (GH-15139)

(cherry picked from commit 4f9ffc9d1a6a293563deaaaaf4a13331302219b4)

Co-authored-by: Raymond Hettinger <rhettinger@users.noreply.github.com>
2 files changed