docs(tutorial): text following a node requires a dot

public/docs/dart/latest/tutorial/toh-pt3.jade

@@ -164,7 +164,7 @@ code-example(format=".").
 :marked
  The two components won't coordinate until we bind the `selectedHero` property of the `AppComponent`
  to the `HeroDetailComponent` element's `hero` property  like this:
-code-example(format=".")
+code-example(format=".").
   <my-hero-detail [hero]="selectedHero"></my-hero-detail>
 :marked
   The `AppComponent`’s template should now look like this