Doc: update v13 release notes through today, do a copy-editing pass.
Also set the release date ... hopefully we won't have to change that.
Branch
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REL_13_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/3965de54e718600a4703233936e56a3202caf73f
Modified Files
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doc/src/sgml/release-13.sgml | 690 ++++++++++++++++++++++---------------------
1 file changed, 351 insertions(+), 339 deletions(-)