Add a note about SelctionToggled vs SelectedChanged

src/textual/widgets/_selection_list.py

@@ -183,6 +183,14 @@ class SelectionList(Generic[SelectionType], OptionList):
 
         Can be handled using `on_selection_list_selection_toggled` in a subclass of
         `SelectionList` or in a parent node in the DOM.
+
+        Note:
+            This message is only sent if the selection is toggled by user
+            interaction. See
+            [`SelectedChanged`][textual.widgets.SelectionList.SelectedChanged]
+            for a message sent when any change (selected or deselected,
+            either by user interaction or by API calls) is made to the
+            selected values.
         """
 
     @dataclass