Use Title: meta instead of explicit <h1>

Author: tantek

css-timing-1/Overview.bs

@@ -1,6 +1,5 @@
-<h1>CSS Timing Functions Level 1</h1>
-
 <pre class=metadata>
+Title: CSS Timing Functions Level 1
 Status: ED
 Work Status: Refining
 Shortname: css-timing