[css2] Added a ".html" to make a link work better.

--HG--
extra : convert_revision : svn%3A73dc7c4b-06e6-40f3-b4f7-9ed1dbc14bfc/trunk%402262

Author: bert-github

css2/cover.src

@@ -224,7 +224,8 @@ in this specification.</p>
   <p>Since implementations are not expected to support multiple IDs
   per element soon, this feature may be made informative. The W3C
   Selectors specification will continue to have this feature
-  normatively. (<a href="selector#id-selectors">Section 5.8.4.</a>)
+  normatively. (<a href="selector.html#id-selectors">Section
+  5.8.4.</a>)
  </dd>
 </dl>