DOCS - "\d mytable" also shows any publications that publish mytable

I was looking at "\d" documentation yesterday.

The psql table describe (e.g. "\d mytable") will display a list of any
"Publications:" that are publishing the specified table. Somehow, this
ability had escaped being mentioned in the psql reference
documentation.

Here is a trivial patch to fix that omission.

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Kind Regards,
Peter Smith.
Fujitsu Australia