clarify wording from jm feedback

Author: shuangela

source/reference/method/MongoDBCollection-find.txt

@@ -52,9 +52,8 @@ Parameters
 
      * - batchSize
        - integer
-       - The maximum number of documents within each batch returned in a query result, which applies 
-         to the ``aggregate`` command. By default, the ``aggregate`` command has an initial batch size of 
-         `101`` documents and a maximum size of 16 mebibytes for each subsequent batch. This
+       - The maximum number of documents to return in the first batch. By default, the ``find()`` 
+         command has an initial batch size of `101`` documents. This
          option can enforce a smaller limit than 16 mebibytes, but not a larger
          one. If you set ``batchSize`` to a limit that results in batches larger than
          16 MiB, this option has no effect.

source/reference/method/MongoDBDatabase-aggregate.txt

@@ -54,8 +54,8 @@ Parameters
 
      * - batchSize
        - integer
-       - The maximum number of documents within each batch returned in a query result, which applies 
-         to the ``aggregate`` command. By default, the ``aggregate`` command has an initial batch size of 
+       - The maximum number of documents within each batch returned in a query result.
+         By default, the ``aggregate`` command has an initial batch size of 
          `101`` documents and a maximum size of 16 mebibytes for each subsequent batch. This
          option can enforce a smaller limit than 16 mebibytes, but not a larger
          one. If you set ``batchSize`` to a limit that results in batches larger than