docs(displaying-data): remind to import Hero class (#2975) (#2984)

Author: wardbell

public/docs/ts/latest/guide/displaying-data.jade

@@ -202,7 +202,7 @@ block hero-class
 :marked
   ## Using the Hero class
 
-  The `heroes` property in the component can now use the `Hero` class to return !{_an} !{_array}
+  After importing the `Hero` class, the `AppComponent.heroes` property can return a _typed_ !{_array}
   of `Hero` objects:
 
 +makeExcerpt('app/app.component.3.ts', 'heroes')