gh-151914: Reorganize the curses entries in What's New in Python 3.16 (GH-153397)

gh-151914: Reorganize the curses entries in What's New in Python 3.16 (GH-153397)

Order the curses entries from the most important and general to the more
specialized: wide-character and complexchar/complexstr support first, then
multiple-terminal support, attributes and colors, screen and window management,
input handling, and finally introspection.  The curses.textpad.Textbox entry,
belonging to a separate submodule, moves to the end.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>