DOCSP-47836 clarify batchsize description (#96)

* change batchsize description

* nr feedback

* fix wrapping

* wrapping

* Empty-Commit

* tech feedback

Author: shuangela

source/read/change-streams.txt

@@ -147,8 +147,13 @@ of the watch functions:
      - Description
 
    * - ``batchSize``
-     - | Sets the number of documents to return per batch.
-
+     - | The maximum number of documents that a change stream can
+         return in each batch, which applies to the watch function. 
+         By default, watch functions have an initial batch size of ``101``
+         documents and a maximum size of 16 mebibytes (MiB) for each subsequent 
+         batch. This option can enforce a smaller limit than 16 MiB, but not a 
+         larger one. For details, see :manual:`Cursor Batches </tutorial/iterate-a-cursor/#std-label-cursor-batches>`
+         in the {+mdb-server+} manual.  
 
    * - ``comment``
      - | Specifies a comment to attach to the operation.