DOCSP-24946 Clarifies estimatedTotalBytes and estimatedCopiedBytes (#253)

* DOCSP-24946 Clarifies estimatedTotalBytes and estimatedCopiedBytes

* Fixes per Sarah

Author: kennethdyer

source/includes/api/tables/progress-response.rst

@@ -51,20 +51,21 @@
 
    * - ``collectionCopy``
      - object
-     - Describes the total amount of data being copied and the
-       amount that has already been copied to the destination cluster.
+     - Estimates the total amount of data being copied from collections and the
+       amount that has already been copied to the destination cluster
 
    * - ``collectionCopy``
        ``.estimatedTotalBytes``
      - integer
-     - Estimated total number of bytes to be copied globally by all ``mongosync``
-       instances.
+     - Estimated total number of bytes to be copied globally by all
+       ``mongosync`` instances during the initial copying of collections.
 
    * - ``collectionCopy``
        ``.estimatedCopiedBytes``
      - integer
-     - Estimated number of bytes which have been copied to the
-       destination cluster by this ``mongosync`` instance.
+     - Estimated number of bytes which have been copied to the destination
+       cluster by this ``mongosync`` instance during the initial copying of 
+       collections.
 
        To calculate the total estimated progress as a percentage, add the value
        of the ``estimatedCopiedBytes`` field for each ``mongosync`` instance