fix broken example link

docs/4.0/examples/index.md

@@ -38,8 +38,8 @@ Examples that focus on implementing uses of built-in components provided by Boot
   <div class="col-6 col-md-4">
     <a href="{{ site.baseurl }}/docs/{{ site.docs_version }}/examples/narrow-jumbotron/">
       <img class="img-thumbnail" src="{{ site.baseurl }}/docs/{{ site.docs_version }}/examples/screenshots/jumbotron-narrow.jpg" alt="">
+      <h4>Narrow jumbotron</h4>
     </a>
-    <h4>Narrow jumbotron</h4>
     <p>Build a more custom page by narrowing the default container and jumbotron.</p>
   </div>
 </div>