pgsql: Fix various typos, grammar and code style in comments and docs

Fix various typos, grammar and code style in comments and docs

This fixes a set of issues that have accumulated over the past months
(or years) in various code areas.  Most fixes are related to some recent
additions, as of the development of v15.

Author: Justin Pryzby
Discussion: https://postgr.es/m/20220124030001.GQ23027@telsasoft.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/410aa248e5a883fde4832999cc9b23c7ace0f2ff

Modified Files
--------------
doc/src/sgml/config.sgml                           |   4 +-
doc/src/sgml/ddl.sgml                              |   6 +-
doc/src/sgml/func.sgml                             | 145 +++++++++++----------
doc/src/sgml/glossary.sgml                         |  32 ++---
doc/src/sgml/indexam.sgml                          |   2 +-
doc/src/sgml/perform.sgml                          |   2 +-
doc/src/sgml/postgres-fdw.sgml                     |  12 +-
doc/src/sgml/protocol.sgml                         |  10 +-
doc/src/sgml/ref/alter_publication.sgml            |   4 +-
doc/src/sgml/ref/create_publication.sgml           |   8 +-
doc/src/sgml/ref/pg_receivewal.sgml                |  11 +-
doc/src/sgml/ref/pgbench.sgml                      |   4 +-
doc/src/sgml/ref/pgupgrade.sgml                    |   2 +-
doc/src/sgml/ref/select_into.sgml                  |   2 +-
src/backend/access/gin/ginget.c                    |   2 +-
src/backend/access/heap/heapam.c                   |   2 +-
src/backend/access/transam/xlog.c                  |   1 -
src/backend/catalog/pg_publication.c               |   2 +-
src/backend/commands/cluster.c                     |   2 +-
src/backend/commands/indexcmds.c                   |   2 +-
src/backend/commands/publicationcmds.c             |   2 +-
src/backend/commands/subscriptioncmds.c            |   2 +-
src/backend/optimizer/util/appendinfo.c            |   2 +-
src/backend/optimizer/util/inherit.c               |   2 +-
src/backend/replication/logical/logicalfuncs.c     |   2 +-
src/backend/replication/logical/reorderbuffer.c    |   2 +-
src/backend/replication/logical/snapbuild.c        |   2 +-
src/backend/replication/logical/worker.c           |   8 +-
src/backend/statistics/extended_stats.c            |   2 +-
src/backend/statistics/mcv.c                       |   8 +-
src/backend/storage/sync/sync.c                    |   1 -
src/backend/utils/activity/backend_progress.c      |   4 +-
src/backend/utils/activity/backend_status.c        |   2 +-
src/backend/utils/activity/wait_event.c            |   2 +-
src/bin/psql/describe.c                            |   4 +-
src/include/replication/pgoutput.h                 |   2 +-
src/include/utils/dynahash.h                       |   5 +-
src/pl/plperl/plperl.c                             |   2 +-
src/port/pgcheckdir.c                              |   4 +-
.../unsafe_tests/expected/alter_system_table.out   |   4 +-
.../unsafe_tests/sql/alter_system_table.sql        |   4 +-
src/test/regress/expected/sysviews.out             |   2 +-
src/test/regress/sql/sysviews.sql                  |   2 +-
src/tools/msvc/vcregress.pl                        |   4 +-
44 files changed, 164 insertions(+), 165 deletions(-)