[scroll-animations-1] Add majidvp as editor

Adding myself (majidvp@google.com) as editor to the spec.
Also moving Stephen (smcgruer@google.com) to former editor section.

Author: majido

scroll-animations-1/Overview.bs

@@ -12,9 +12,10 @@ Abstract: Defines an API and markup for creating animations that are either
           triggered by or tied to the scroll offset of a scroll container.
 Editor: Brian Birtles <bbirtles@mozilla.com>
 Editor: Botond Ballo <botond@mozilla.com>
-Editor: Stephen McGruer <smcgruer@google.com>
 Editor: Antoine Quint <graouts@apple.com>
+Editor: Majid Valipour <majidvp@google.com>, w3cid 81464
 Former editor: Mantaroh Yoshinaga
+Former editor: Stephen McGruer <smcgruer@google.com>
 </pre>
 <pre class=anchors>
 urlPrefix: https://w3c.github.io/web-animations/; type: dfn; spec: web-animations