[css-fonts-4] cleanup font-anguage-override markup

Author: svgeesus

css-fonts-4/Overview.bs

@@ -4606,8 +4606,10 @@ Normally, authors can control the use of language-specific glyph substitutions a
 by setting the content language of an element, as <a href="#language-specific-support">described
 	above</a>:
 
+<div class="example">
 <pre>&lt;!-- Display text using S'gaw Karen specific features -->
-&lt;p lang="ksw">...&lt;/p></pre>
+	&lt;p lang="ksw">...&lt;/p></pre>
+</div>
 
 In some cases, authors may need to specify a language system
 that differs from the content language, for example due to the need to mimic another language's