refector: editoral change in ActionOutput

Co-authored-by: Jan Romann <[email protected]>

Author: relu91

index.html

@@ -1333,7 +1333,7 @@ <h2>The <dfn>ActionInteractionOutput</dfn> interface</h2>
           [=in parallel=].
         </li>
         <li>
-          If invoking this method is not supported (e.g., synchronous action)
+          If invoking this method is not supported (e.g., because the action is synchronous)
           [=reject=] |promise| with a {{NotSupportedError}} and stop.
         </li>
         <li>