maint: Add missing NEWS items.
maint: Add missing NEWS items.

* NEWS: Reformat slightly, for easier pasting into Markdown
format GitHub release announcement.
Add forgotten items since last release.

Signed-off-by: Gary V. Vaughan <f9023000f29773649f3850298becb9544b5fd6a9@gnu.org>

gvvaughan/slingshot