[css-contain] property names linkified (#2801)

'counter-increment' and 'content' property names are now working links.

resolves #2800

Author: ewilligers

css-contain-1/Overview.bs

@@ -15,7 +15,6 @@ Editor: Tab Atkins, Google, http://xanthir.com/contact/, w3cid 42199
 Editor: Florian Rivoal, On behalf of Bloomberg, https://florian.rivoal.net/, w3cid 43241
 Abstract: This CSS module describes the 'contain' property, which indicates that the element's subtree is independent of the rest of the page. This enables heavy optimizations by user agents when used well.
 Ignored Terms: scrollWidth, scrollHeight, clientWidth, clientHeight
-Link Defaults: css-lists-3 (property) counter-increment
 </pre>
 <pre class="anchors">
 spec: css2; urlPrefix: https://www.w3.org/TR/CSS2/
@@ -30,10 +29,10 @@ spec: css-backgrounds-3;
 	type: dfn; url: https://drafts.csswg.org/css-backgrounds-3/#corner-clipping; text: corner clipping
 </pre>
 <pre class=link-defaults>
-spec:css21; type:property; text:content
-spec:css21; type:property; text:counter-increment
 spec:css21; type:dfn; text:stacking context
+spec:css-content; type:property; text:content
 spec:css-display-3; type:property; text:display
+spec:css-lists-3; type:property; text:counter-increment
 </pre>
 <h2 id='intro'>
 Introduction</h2>