User mapping security

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/10/postgres-fdw.html
Description:

Regarding the documentation pages
https://www.postgresql.org/docs/10/postgres-fdw.html?origin_team=T02HEPYKQ
and https://www.postgresql.org/docs/10/sql-createusermapping.html

I suppose it should be warned on the pages that foreign credentials with be
stored as simple text and will be available for viewing in pg_user_mappings.