[css-content] attempt to get better links for normal and none

Author: dauwhe

css-content/Overview.bs

@@ -110,7 +110,7 @@ Inserting and replacing content with the 'content' property</h2>
 	or replace it with arbitrary inline content
 	(text and images).
 
-	<dl dfn-for="content, <content-list>" dfn-type=value>
+	<dl dfn-for="content" dfn-type=value>
 		<dt><dfn>normal</dfn>
 		<dd>
 			For an element, this computes to ''content/contents''.