title: paragraph with 'lead' bootstrap 4 class with button inside
body: <p>In the Bootstrap 4 docs about Jumbotron they show in the example the following:</p>
  
  <pre><code>&lt;p class="lead"&gt;
    &lt;a class="btn btn-primary btn-lg" href="#" role="button"&gt;Learn more&lt;/a&gt;
  &lt;/p&gt;
  </code></pre>
  
  <p>What is the need of a paragraph here?
  And why use the 'lead' class? It seems to do nothing with the button.</p>