Add myself, Antoine Quint, as editor.

Author: graouts

Overview.bs

@@ -12,6 +12,7 @@ Editor: Brian Birtles <bbirtles@mozilla.com>
 Editor: Botond Ballo <botond@mozilla.com>
 Editor: Mantaroh Yoshinaga <mantaroh@mozilla.com>
 Editor: Stephen McGruer <smcgruer@google.com>
+Editor: Antoine Quint <graouts@apple.com>
 !Issue Tracking: <a href="https://github.com/WICG/scroll-animations/issues">GitHub Issues</a>
 </pre>
 <pre class=anchors>