Remove custom example plugin. (#25784)

docs/4.0/components/jumbotron.md

@@ -7,7 +7,7 @@ group: components
 
 A lightweight, flexible component that can optionally extend the entire viewport to showcase key marketing messages on your site.
 
-{% example html %}
+{% capture example %}
 <div class="jumbotron">
   <h1 class="display-4">Hello, world!</h1>
   <p class="lead">This is a simple hero unit, a simple jumbotron-style component for calling extra attention to featured content or information.</p>
@@ -17,15 +17,17 @@ A lightweight, flexible component that can optionally extend the entire viewport
     <a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a>
   </p>
 </div>
-{% endexample %}
+{% endcapture %}
+{% include example.html content=example %}
 
 To make the jumbotron full width, and without rounded corners, add the `.jumbotron-fluid` modifier class and add a `.container` or `.container-fluid` within.
 
-{% example html %}
+{% capture example %}
 <div class="jumbotron jumbotron-fluid">
   <div class="container">
     <h1 class="display-4">Fluid jumbotron</h1>
     <p class="lead">This is a modified jumbotron that occupies the entire horizontal space of its parent.</p>
   </div>
 </div>
-{% endexample %}
+{% endcapture %}
+{% include example.html content=example %}