DOCSP-16321 fix dupe atomicity section on data modeling

Author: andf-mongodb

source/core/data-modeling-introduction.txt

@@ -95,12 +95,15 @@ A denormalized data model with embedded data combines all related data
 in a single document instead of normalizing across multiple documents
 and collections. This data model facilitates atomic operations.
 
-.. include:: /includes/extracts/concurrent-operations-multi-document-writes.rst
+For details regarding transactions in MongoDB, see the
+:doc:`/core/transactions` page.
 
 Multi-Document Transactions
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-.. include:: /includes/extracts/transactions-intro.rst
+.. include:: /includes/extracts/concurrent-operations-multi-document-writes.rst
+
+.. include:: /includes/extracts/transactions-usage.rst
 
 .. seealso:: :ref:`Atomicity Considerations <data-model-atomicity>`