Doc: Update documentation for modifying postgres_fdw foreign tables.
Document that they can be modified using COPY as well.
Back-patch to v11 where commit added support for COPY in
postgres_fdw.
<para>
Now you need only <command>SELECT</command> from a foreign table to access
the data stored in its underlying remote table. You can also modify
- the remote table using <command>INSERT</command>, <command>UPDATE</command>, or
- <command>DELETE</command>. (Of course, the remote user you have specified
- in your user mapping must have privileges to do these things.)
+ the remote table using <command>INSERT</command>, <command>UPDATE</command>,
+ <command>DELETE</command>, or <command>COPY</command>. (Of course, the
+ remote user you have specified in your user mapping must have privileges to
+ do these things.)
</para>
<para>
