Add Reilly as the editor, retire Domenic (#160)

With Domenic departing Google he is stepping down from his role as
editor of this specification. We thank him for his service to the web
community in this and all of his other work over the years.

With the Chair's permission I nominate myself to take over the role of
editor for this specification.

Author: reillyeon

index.bs

@@ -6,7 +6,8 @@ Status: CG-DRAFT
 Group: webml
 Repository: webmachinelearning/prompt-api
 URL: https://webmachinelearning.github.io/prompt-api
-Editor: Domenic Denicola, Google https://google.com, d@domenic.me, https://domenic.me/
+Editor: Reilly Grant 83788, Google https://www.google.com, reillyg@google.com
+Former editor: Domenic Denicola 52873, Google https://www.google.com/, d@domenic.me, https://domenic.me/
 Abstract: The prompt API gives web pages the ability to directly prompt a language model
 Markup Shorthands: markdown yes, css no
 Complain About: accidental-2119 yes, missing-example-ids yes