[css-transitions-2][editorial] Fixed Bikeshed issue

Author: SebastianZ

css-transitions-2/Overview.bs

@@ -19,6 +19,7 @@ urlPrefix: https://dom.spec.whatwg.org/; type: dfn; spec: dom
     text: event target
 </pre>
 <pre class=link-defaults>
+spec:css-borders-4; type:property; text:border-left-width
 spec:css-transitions-1; type:value; text:all
 spec:css-transitions-1; type:dfn; text:cancel
 spec:html; type:dfn; text:being rendered