notification: Improve wording around DBus Activation

data/org.freedesktop.portal.Notification.xml

@@ -35,8 +35,15 @@
 
       Notifications can specify actions that can be activated by the
       user. Actions whose name starts with 'app.' are assumed to be
-      exported and will be activated via the ActivateAction()
-      method in the org.freedesktop.Application interface. Other
+      exported (without the 'app.' prefix) and will be activated via
+      `DBus Activation
+      <https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s08.html>`_
+      using ``ActivateAction()`` method in the
+      ``org.freedesktop.Application`` interface. An `activation-token` for
+      ` XDG Activation
+      <https://gitlab.freedesktop.org/wayland/wayland-protocols/-/blob/main/staging/xdg-activation/xdg-activation-v1.xml>`_
+      and an application-defined `target` is passed when activating the action.
+      Other
       actions are activated by sending the
       #org.freedesktop.portal.Notification::ActionInvoked signal
       to the application.