pgsql: docs: Explain how to silence overly verbose messages by fop

docs: Explain how to silence overly verbose messages by fop

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: /messages/by-id/20230324194701.dqkzcdtlcikseo22@awork3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/642d8779768ecddc2917747940885d11f844f6e9

Modified Files
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doc/src/sgml/docguide.sgml | 10 ++++++++++
1 file changed, 10 insertions(+)