DOCSP-26559: clarify what full document property does (#63)

* DOCSP-26559: clarify what full document property does

* CC PR fixes 1

* CC PR fixes 2

* CC suggestions

Author: rustagir

source/source-connector/configuration-properties/change-stream.txt

@@ -41,12 +41,14 @@ Settings
        |
        | **Description:**
        | An array of aggregation pipelines to run in your change stream.
+         You must configure this setting for the change stream
+         event document, not the ``fullDocument`` field.
 
        .. example::
 
           .. code-block:: none
 
-             [{"$match": {"operationType": "insert"}}, {"$addFields": {"Kafka": "Rules!"}}]
+             [{"$match": { "$and": [{"operationType": "insert"}, {"fullDocument.eventId": 1404 }] } }]
 
        .. tip:: Additional Examples
 
@@ -82,11 +84,16 @@ Settings
      - | **Type:** boolean
        |
        | **Description:**
-       | Whether to publish the changed document instead of the full change
-         stream document. When set to ``true``, the connector
-         automatically sets the ``change.stream.full.document`` property to
-         ``updateLookup`` to receive the updated documents.
-       |
+       | Whether to return only the ``fullDocument`` field from the
+         change stream event document produced by any update event. The ``fullDocument`` field
+         contains the most current version of the updated document. To
+         learn more about the ``fullDocument`` field, see the :rapid:`Server
+         manual page on update events </reference/change-events/update/>`.
+       | When set to ``true``, the connector overrides the
+         ``change.stream.full.document`` setting and sets it to
+         ``updateLookup`` so that the ``fullDocument`` field contains
+         updated documents.
+
        | **Default**: ``false``
        | **Accepted Values**: ``true`` or ``false``