DOCSP-3795: describe wc for retry committransaction (#3721)

* DOCSP-3795: describe wc for retry committransaction

* JW format fix

Author: rustagir

source/core/transactions.txt

@@ -663,6 +663,11 @@ values, including:
 
    .. include:: /includes/write-concern-majority-and-transactions.rst
 
+   Regardless of the :ref:`write concern specified for the
+   transaction <transactions-write-concern>`, the driver applies
+   :writeconcern:`w: "majority" <"majority">` as the write concern when
+   retrying :dbcommand:`commitTransaction`.
+
 General Information
 -------------------