Add alert divider (<hr>) example in docs (#21673)

* Add alert divider (<hr />)example in docs

* <hr/> => <hr> per @vsn4ik suggestion

diff --git a/docs/components/alerts.md b/docs/components/alerts.md
index da72e322e519c5fea7f1a855f71dce38ae74e713..dae4ec7d36e8c82018d596817301709b0fc3fbb7 100644 (file)
--- a/docs/components/alerts.md
+++ b/docs/components/alerts.md
@@ -55,12 +55,13 @@ Use the `.alert-link` utility class to quickly provide matching colored links wi
 
 ### Additional content
 
-Alerts can also contain additional HTML elements like headings and paragraphs.
+Alerts can also contain additional HTML elements like headings, paragraphs and dividers.
 
 {% example html %}
 <div class="alert alert-success" role="alert">
   <h4 class="alert-heading">Well done!</h4>
   <p>Aww yeah, you successfully read this important alert message. This example text is going to run a bit longer so that you can see how spacing within an alert works with this kind of content.</p>
+  <hr>
   <p class="mb-0">Whenever you need to, be sure to use margin utilities to keep things nice and tidy.</p>
 </div>
 {% endexample %}