[css-containment] Add myself as an Editor

Author: frivoal

css-containment/Overview.bs

@@ -8,6 +8,7 @@ Work Status: Exploring
 Group: csswg
 ED: https://drafts.csswg.org/css-containment/
 Editor: Tab Atkins, Google, http://xanthir.com/contact/
+Editor: Florian Rivoal, On behalf of Bloomberg, florian@rivoal.net, http://florian.rivoal.net/
 Abstract: This CSS module describes the 'contain' property, which indicates that the element's subtree is independent of the rest of the page. This enables heavy optimizations by user agents when used well.
 Ignored Terms: scrollWidth, scrollHeight, clientWidth, clientHeight, formatting context
 Link Defaults: css-lists-3 (property) counter-increment, css-content-3 (property) string-set