Обсуждение: pgsql: doc: Release notes refinements

doc: Release notes refinements

In particular, make some more precise links for some major items.

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/3e3e32a1c160ec4e2342068515dfaf1dd04c6078

Modified Files
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doc/src/sgml/ref/alter_table.sgml |  2 +-
doc/src/sgml/release-12.sgml      | 23 ++++++++++++-----------
2 files changed, 13 insertions(+), 12 deletions(-)