[css-content] add explict href for replaced element link to placate bikeshed

Author: dauwhe

css-content/Overview.bs

@@ -126,13 +126,13 @@ Inserting and replacing content with the 'content' property</h2>
 
 			In neither case does it prevent any pseudo-elements which have this element or pseudo-element as an <a>originating element</a> from being generated.
 
-		<dt><dfn><<content-replacement>></dfn>
+		<dt><dfn type><<content-replacement>></dfn>
 		<dd id=replaced>
 			Equal to:
 
 			<pre class=prod><<image>></pre>
 
-			Makes the element or pseudo-element a <a>replaced element</a>,
+			Makes the element or pseudo-element a <a href="https://www.w3.org/TR/CSS2/conform.html#replaced-element">replaced element</a>,
 			filled with the specified <<image>>.
 			Its normal contents are suppressed
 			and do not generate boxes,