Doc: Update link to the mentioned subsection

This updates the link from pg_createsubscriber to initial data sync
to actually link to the subsection in question as opposed to the
main logical replication section.

Author: Pavel Luzanov <p.luzanov@postgrespro.ru>
Discussion: https://postgr.es/m/a4af555a-ac60-4416-877d-0440d29b8763@postgrespro.ru

Author: danielgustafsson

doc/src/sgml/ref/pg_createsubscriber.sgml

@@ -69,8 +69,8 @@ PostgreSQL documentation
    spent synchronizing data is usually a large amount of changes to be applied
    (that were produced during the initial data copy), which increases even
    more the time when the logical replica will be available. For smaller
-   databases, <link linkend="logical-replication">initial data
-   synchronization</link> is recommended.
+   databases, <link linkend="logical-replication-row-filter-initial-data-sync">
+   initial data synchronization</link> is recommended.
   </para>
  </refsect1>