pgsql: doc PG 17 relnotes: various fixes

doc PG 17 relnotes: various fixes

Fixes suggested by David Rowley, Bertrand Drouvot, Masahiko
Sawada, Richard Guo, jian he, Dagfinn Ilmari Mannsåker

Backpatch-through: master

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/45ea5b0a2732849ef8bfb695808943d0d940abeb

Modified Files
--------------
doc/src/sgml/release-17.sgml | 62 ++++++++++++++++++++++++--------------------
1 file changed, 34 insertions(+), 28 deletions(-)