update changelog with new names

Author: snbianco

CHANGES.rst

@@ -64,7 +64,7 @@ mast
 
 - Improved robustness of PanSTARRS column metadata parsing. This prevents metadata-related query errors. [#3485]
 
-- Added a new ``Observations.get_cloud_missions()`` method for querying cloud-supported MAST missions, alongside 
+- Add a new ``Observations.list_cloud_datasets()`` method for querying cloud-supported MAST datasets, alongside 
   improvements to cloud download handling. [#3488]
 
 jplspec