doc revert of commit 1703726488.  Change was applied to irrelevant
branches, and was not detailed enough to be helpful in relevant
branches.

Reported-by: Peter Eisentraut, Noah Misch

Discussion: https://postgr.es/m/a2dc9de4-24fc-3222-87d3-0def8057d7d8@enterprisedb.com

Backpatch-through: 10