DOCS-13880 indicate requirement of matching source and target databases on the same primary shard

Author: ajhuh-mdb

source/includes/extracts-mongos-operations.yaml

@@ -24,8 +24,9 @@ content: |
 
    .. note::
 
-      You cannot rename a sharded collection. You can however rename an
-      unsharded collection in a sharded cluster.
+      You cannot rename a sharded collection. However, you can rename an
+      unsharded collection in a sharded cluster as long as the source 
+      and target databases are on the same primary shard.
 
 ---
 ref: mongos-operations-wc-create