add cross link

Author: rustagir

docs/upgrade.txt

@@ -127,6 +127,9 @@ This library version introduces the following breaking changes:
   method results before hydrating a Model instance. When passing a complex query
   filter, use the ``DB::where()`` method instead of ``Model::raw()``.
 
+  Starting in v5.3, you can disable automatic conversion of ``id`` to
+  ``_id`` for embedded documents. To learn more, see the :ref:`laravel-disable-id-alias` section of the Connection Options guide..
+
 - Removes support for the ``$collection`` property. The following code shows
   how to assign a MongoDB collection to a variable in your ``User`` class in
   older versions compared to v5.0: