unsupported operation is attempted (for example, writing to a file open
only for reading).

Fix reST in NEWS, and remove NEWS.help (all committers should now know reST anyway, and for those who do not, there is Documenting Python.)

- The entry about shutil.copytree is just a revert of r84524 which
looks like an unfinished edition.
- The use of gender-neutral language (s/his/their/) removes the
implicit assumption that programmer == male (change agreed by Antoine).
- Other changes should be uncontroversial fixes.

I haven’t rewrapped under 80 lines to keep the diffs readable; I’ll
rewrap later.