pgsql: Misc documentation fixes.

Misc documentation fixes.

- Misc grammar and punctuation fixes.

- Stylistic cleanup: use spaces between function arguments and JSON fields
in examples. For example "foo(a,b)" -> "foo(a, b)". Add semicolon after
last END in a few PL/pgSQL examples that were missing them.

- Make sentence that talked about "..." and ".." operators more clear,
by avoiding to end the sentence with "..". That makes it look the same
as "..."

- Fix syntax description for HAVING: HAVING conditions cannot be repeated

Patch by Justin Pryzby, per Yaroslav Schekin's report. Backpatch to all
supported versions, to the extent that the patch applies easily.

Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/c5f42daa6077a4c309c5280a47d0e114c12dc572

Modified Files
--------------
doc/src/sgml/catalogs.sgml | 2 +-
doc/src/sgml/config.sgml | 4 ++--
doc/src/sgml/dblink.sgml | 8 ++++----
doc/src/sgml/func.sgml | 32 ++++++++++++++++----------------
doc/src/sgml/gin.sgml | 2 +-
doc/src/sgml/high-availability.sgml | 2 +-
doc/src/sgml/hstore.sgml | 10 +++++-----
doc/src/sgml/indexam.sgml | 2 +-
doc/src/sgml/isn.sgml | 2 +-
doc/src/sgml/ltree.sgml | 12 ++++++------
doc/src/sgml/mvcc.sgml | 2 +-
doc/src/sgml/parallel.sgml | 2 +-
doc/src/sgml/plpgsql.sgml | 12 ++++++------
doc/src/sgml/protocol.sgml | 2 +-
doc/src/sgml/ref/select.sgml | 2 +-
doc/src/sgml/ref/select_into.sgml | 2 +-
doc/src/sgml/rules.sgml | 6 +++---
doc/src/sgml/seg.sgml | 4 ++--
doc/src/sgml/textsearch.sgml | 30 +++++++++++++++---------------
19 files changed, 69 insertions(+), 69 deletions(-)