[DOCSP-47795] Change batchsize description (#392)

* change batchsize description

* address feedback

* remove period

* remove typo

* fix wrap

* wrap

* ch feedback

* ch feedback

* fix spacing

Author: shuangela

source/reference/methods.txt

@@ -497,8 +497,16 @@ Cursor Methods
        .. arrayAccess
 
    * - :method:`cursor.batchSize()`
-     - Controls the number of documents MongoDB will return to the
-       client in a single network message.
+     - Specifies the maximum number of documents MongoDB can return to the 
+       client within each batch returned in a query result. By default, the initial batch
+       size is the lesser of ``101`` documents or 16 mebibytes (MiB) worth of documents.
+       Subsequent batches have a maximum size of 16 MiB. This option can enforce a smaller
+       limit than 16 MiB, but not a larger one. When set, the
+       ``batchSize`` is the lesser of ``batchSize`` documents or 16 MiB worth of
+       documents.
+
+       A ``batchSize`` of ``0`` means that the cursor is established, but no documents 
+       are returned in the first batch. 
 
        The following example query returns results in batches of
        100: