[mediaqueries] Resolve bikeshed ambiguity

Author: frivoal

mediaqueries/Overview.bs

@@ -971,10 +971,14 @@ orientation</h3>
 	Type: discrete
 	</pre>
 
-	The 'orientation' media feature is ''portrait''
-	when the value of the 'height' media feature is greater than or equal to
-	the value of the 'width' media feature.
-	Otherwise 'orientation' is ''landscape''.
+	<dl dfn-type=value dfn-for="@media/orientation">
+		<dt><dfn>portrait</dfn>
+		<dd>The 'orientation' media feature is ''portrait''
+		when the value of the 'height' media feature is greater than or equal to
+		the value of the 'width' media feature.
+		<dt><dfn>landscape</dfn>
+		<dd>Otherwise 'orientation' is ''landscape''.
+	</dl>
 
 	<div class="example">
 		The following media query tests for “portrait” orientation,