[web-animations-2] Define a title as in other specs

lahmatiy · birtles · commit 5005f2a2da48 · 2019-08-31T12:47:48.000+09:00
diff --git a/web-animations-2/Overview.bs b/web-animations-2/Overview.bs
@@ -1,5 +1,5 @@
-<h1>Web Animations Level 2</h1>
 <pre class='metadata'>
+Title: Web Animations Level 2
 Status: UD
 Warning: not ready
 Work Status: Exploring
