[css-highlights-api] markup fixes

Author: frivoal

css-highlight-api-1/Overview.bs

@@ -237,7 +237,7 @@ Registering Custom Highlights</h3>
 	However, using more than one name to style a highlight will assign the highlight multiple different sets
 	of styles, without a way to control the stacking order of conflicting styles within these sets
 	during [[#painting|painting]]. This may be limiting for authors and may cause confusing painting behavior
-	(see the [[#styling-problems-with-multiple-names-per-highlight|example]] below for more context). Therefore,
+	(see the <a href="#styling-problems-with-multiple-names-per-highlight">example</a> below for more context). Therefore,
 	<b>it is recommended that authors only use one name per highlight during styling</b>.
 	<div class=example id=styling-problems-with-multiple-names-per-highlight>
 		<xmp highlight=html>