DOCSP-15576 adding reference to adl for lookup on sharded collection

Author: kanchana-mongodb

source/reference/operator/aggregation/lookup.txt

@@ -284,6 +284,12 @@ Alternatively, or to join multiple sharded collections, consider:
 - If possible, using an :ref:`embedded data model
   <data-modeling-embedding>` that removes the need to join collections.
 
+- If possible, using an `Atlas Data Lake 
+  <https://docs.mongodb.com/datalake/>`__ 
+  `$lookup 
+  <https://docs.mongodb.com/datalake/reference/pipeline/lookup-stage/>`__ 
+  pipeline stage to lookup a sharded collection.
+
 Examples
 --------