Use Title: meta instead of explicit <h1>

Author: tantek

css-backgrounds-3/Overview.src.html

@@ -1,6 +1,5 @@
-<h1>CSS Backgrounds and Borders Module Level 3</h1>
-
 <pre class='metadata'>
+Title: CSS Backgrounds and Borders Module Level 3
 Status: CR
 Date: 2017-10-17
 Deadline:  2017-11-30