doc: clarify menu item properties not available top-level (#15458)

docs/api/menu-item.md

@@ -108,6 +108,8 @@ When specifying a `role` on macOS, `label` and `accelerator` are the only
 options that will affect the menu item. All other options will be ignored.
 Lowercase `role`, e.g. `toggledevtools`, is still supported.
 
+**Nota Bene:** The `enabled` and `visibility` properties are not available for top-level menu items in the tray on MacOS.
+
 ### Instance Properties
 
 The following properties are available on instances of `MenuItem`: