Get rid of "Section.N.N.N" on DOCs

When reading documentation all the time we get something like
See Section 27.4.5
<https://www.postgresql.org/docs/18/progress-reporting.html#VACUUM-PROGRESS-REPORTING>
and Section 27.4.2
<https://www.postgresql.org/docs/18/progress-reporting.html#CLUSTER-PROGRESS-REPORTING>
for
details.
The only way to know what it is that Section is opening and reading its
title.

Wouldn't it be better if we print somethink for better reading like this ?
See VACUUM
<https://www.postgresql.org/docs/18/progress-reporting.html#VACUUM-PROGRESS-REPORTING>
Progress Reporting
<https://www.postgresql.org/docs/18/progress-reporting.html#VACUUM-PROGRESS-REPORTING>
and CLUSTER Progress Reporting
<https://www.postgresql.org/docs/18/progress-reporting.html#CLUSTER-PROGRESS-REPORTING>
for details.

There are places where links are mixed, some of them are auto explanatory,
some don't, like on See Also of VACUUM
vacuumdb <https://www.postgresql.org/docs/18/app-vacuumdb.html>,
Section 19.10.2
<https://www.postgresql.org/docs/18/runtime-config-vacuum.html#RUNTIME-CONFIG-RESOURCE-VACUUM-COST>
, Section 24.1.6
<https://www.postgresql.org/docs/18/routine-vacuuming.html#AUTOVACUUM>,
Section 27.4.5
<https://www.postgresql.org/docs/18/progress-reporting.html#VACUUM-PROGRESS-REPORTING>
, Section 27.4.2
<https://www.postgresql.org/docs/18/progress-reporting.html#CLUSTER-PROGRESS-REPORTING>

For that we need only put a "xreflabel" tag on that target link.

I can create a patch for all of them, but I would like to know why it's
done this way.

regards
Marcos