Update action.md

need to import the action

Author: OwaliShawon

content/docs/en/elements/dialogs/action.md

@@ -15,6 +15,7 @@ The method is part of the [`dialogs` module](https://docs.nativescript.org/api-r
 The `action()` method is available globally. You can call it anywhere in your app.
 
 ```JavaScript
+import { action } from '@nativescript/core/ui/dialogs'
 action("Your message", "Cancel button text", ["Option1", "Option2"])
   .then(result => {
     console.log(result);