PostgreSQL 15 minor documentation improvements

Hello!

I’ve noticed that some changes concerning replacement of archive_command
by archive_library in the documentation for PostgreSQL 15 do not quite
fit in:

1. https://www.postgresql.org/docs/15/continuous-archiving.html
Archiving of these files happens automatically since you have already
configured <varname>archive_library</varname>. - what about using
archive_command? Should it be "...since you have already configured
<varname>archive_library</varname> or <varname>archive_command</varname>"?

2. The same page.
If the archive process has fallen behind because of failures of the
archive library, it will keep retrying until the archive succeeds and
the backup is complete. - again, what about archive command?

3. https://www.postgresql.org/docs/15/app-pgbasebackup.html

All WAL records required for the backup must contain sufficient
full-page writes, which requires you to enable |full_page_writes| on the
primary and not to use a tool in your |archive_library| to remove
full-page writes from WAL files. - the same question here. I believe
that we can write in general: and not to use a tool to remove full-page
writes from WAL files (?).

I have prepared a small patch with possible changes of these places, and
also a separate patch with some improvements concerning missed/inapt
tags. Please have a look.

--
Best regards,
Maxim Yablokov
Technical writer-translator
Postgres Professional <https://postgrespro.com/>