user visible changes on whats-new.rst

Author: Mikejmnez

doc/whats-new.rst

@@ -190,6 +190,9 @@ New Features
   By `Matthew Willson <https://github.com/mjwillson>`_.
 - Added exception handling for invalid files in :py:func:`open_mfdataset`. (:issue:`6736`)
   By `Pratiman Patel <https://github.com/pratiman-91>`_.
+- Improved ``pydap`` backend behavior and performance when using :py:func:`open_dataset`, :py:func:`open_datatree` when downloading
+  dap4 (opendap) data (:issue:`10628`, :pull:`10629`). ``batch=True|False`` is a new  ``backend_kwarg`` that further enables
+  downloading multiple arrays in single response.
 
 Breaking changes
 ~~~~~~~~~~~~~~~~