pgsql: Docs: fix some spelling mistakes and also do some wordsmithing

Docs: fix some spelling mistakes and also do some wordsmithing

All except one of these are new to v15.  Only one of the wordsmithing
changes appears in older versions. The wordsmithing improvement does not
seem significant enough to warrant backpatching.

Author: Justin Pryzby
Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/ac8be0cb957811d04d7564f4d710ceb3e5f2fb9f

Modified Files
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doc/src/sgml/charset.sgml    | 12 ++++++------
doc/src/sgml/ref/initdb.sgml |  2 +-
2 files changed, 7 insertions(+), 7 deletions(-)