[3.12] gh-70795: Rework RLock documentation (GH-103853) (#119437)

gh-70795: Rework RLock documentation (GH-103853)

Attempted to simultaneously reduce verbosity, while more descriptively
describing behavior.

Fix links (RLock acquire/release previously linking to Lock
acquire/release, seems like bad copy pasta).

Add a seealso for with-locks.

Switch section to use bullet points.

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(cherry picked from commit 2fbea81d646688cf438be1dc0be82112a9ae4325)

Co-authored-by: uıɐɾ ʞ ʇɐɯɐs <_@skj.io>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>