Use Title: meta instead of explicit <h1>

Author: tantek

css-shapes-1/Overview.bs

@@ -1,6 +1,5 @@
-<h1>CSS Shapes Module Level 1</h1>
-
 <pre class='metadata'>
+Title: CSS Shapes Module Level 1
 Status: ED
 Work Status: Testing
 Shortname: css-shapes