Merge pull request #17084 from thejameskyle/tjk/3

v4 - Use doge instead of css for <pre> example

docs/content/reboot.md

@@ -111,7 +111,7 @@ The `<pre>` element is reset to remove its `margin-top` and use `rem` units for
 <div class="bd-example">
 {% markdown %}
 <pre>
-.element {
+.example-element {
   margin-bottom: 1rem;
 }
 </pre>