[v8.x backport] doc: fix various nits
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
documentation is changed or added -
commit message follows commit guidelines
Backport of #19743 (proactive).
Commit 1: replace 2 hyphens (--
) by spaced m-dash (—
) as per STYLE_GUIDE.md
.
Commit 2: space infix operators.
Commit 3: unify quotes in inline code spans (use only single quotes).
Commit 4: unify * Returns:
(eliminate deviations).
Commit 5: dedupe spaces.