Update setup-replication-external.mdx (#36382)

Clearer directions around logical replication in PG.

apps/docs/content/guides/database/postgres/setup-replication-external.mdx

@@ -49,7 +49,7 @@ To copy data from before the slot was created, set `copy_data` to `true`.
 
 </Admonition>
 
-4. Add all the tables that you want replicated to the publication.
+4. Now we'll go back to the Supabase DB and add all the tables that you want replicated to the publication.
 
 ```sql
 ALTER PUBLICATION example_pub ADD TABLE example_table;