Take Lea out of the editors, as her term has sadly ended. (#552)

index.bs

@@ -8,9 +8,9 @@ Level: none
 TR: https://www.w3.org/TR/design-principles/
 ED: https://w3ctag.github.io/design-principles/
 Issue Tracking: GitHub https://github.com/w3ctag/design-principles/issues/
-Editor: Lea Verou, Invited Expert, https://lea.verou.me, w3cid 52258
 Editor: Martin Thomson, w3cid 68503, Mozilla https://www.mozilla.org/, https://lowentropy.net/
 Editor: Jeffrey Yasskin, w3cid 72192, Google https://www.google.com/
+Former Editor: Lea Verou, Invited Expert, https://lea.verou.me, w3cid 52258
 Former Editor: Sangwhan Moon, w3cid 42399, Google https://www.google.com/, https://sangwhan.com
 Former Editor: Domenic Denicola, Google https://www.google.com/, https://domenic.me/, d@domenic.me
 Former Editor: Travis Leithead, Microsoft, travil@microsoft.com