PG DOCS - logical replication filtering

Hi.

PSA a PG docs patch that is associated with the logical replication
Row Filters feature which was recently pushed [1].

This patch introduces a new "Filtering" page to give a common place
where all kinds of logical replication filtering can be described.
(e.g. It is envisaged that a "Column Filters" section can be added
sometime in the future).

The main new content for this page is the "Row Filters" section. This
gives a full overview of the new row filter feature, plus examples.

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[1] https://github.com/postgres/postgres/commit/52e4f0cd472d39d07732b99559989ea3b615be78

Kind Regards,
Peter Smith.
Fujitsu Australia