Implement Marc's comments

Author: qcastel

dataikuapi/dss/flow.py

@@ -342,10 +342,10 @@ def add_items(self, items):
         """
         Adds items to this zone.
 
-        The items will automatically be moved from its existing zone. Additional items may be moved to this zone
+        The items will automatically be moved from their existing zones. Additional items may be moved to this zone
         as a result of the operations (notably the recipe generating the `items`).
 
-        :param list of object items, either :class:`dataikuapi.dss.dataset.DSSDataset`, :class:`dataikuapi.dss.managedfolder.DSSManagedFolder`,
+        :param list items: A list of objects, either :class:`dataikuapi.dss.dataset.DSSDataset`, :class:`dataikuapi.dss.managedfolder.DSSManagedFolder`,
                            or :class:`dataikuapi.dss.savedmodel.DSSSavedModel` to add to the zone
         """
         smart_refs = []