[mediaqueries] Markup fixup

Author: frivoal

mediaqueries/Overview.bs

@@ -100,9 +100,9 @@ Units</h3>
 	defined in [[!CSS3VAL]]. For example, the pixel unit represents CSS pixels and
 	not physical pixels.
 
-	Relative units in media queries are based on the initial value, which means
+	Relative units in media queries are based on the <a>initial value</a>, which means
 	that units are never based on results of declarations. For example, in HTML,
-	the ''em'' unit is relative to the initial value of 'font-size',
+	the ''em'' unit is relative to the <a>initial value</a> of 'font-size',
 	defined by the user agent or the user's preferences,
 	not any styling on the page.
 
@@ -938,7 +938,7 @@ width</h3>
 
 		<pre>@media (min-width: 20em) { … }</pre>
 
-		The ''em'' value is relative to the initial value of 'font-size'.
+		The ''em'' value is relative to the <a>initial value</a> of 'font-size'.
 	</div>