[css-shadow-parts-1] Add fergal@chromium.org as editor

Author: fergald

css-shadow-parts-1/Overview.bs

@@ -7,6 +7,7 @@ Status: ED
 Work Status: exploring
 URL: http://drafts.csswg.org/css-shadow-parts/
 Editor: Tab Atkins-Bittner, Google, http://xanthir.com/contact/, w3cid 42199
+Editor: Fergal Daly, Google, fergal@chromium.org
 Abstract: This specification defines the ''::part()'' and ''::theme()'' pseudo-elements on <a>shadow hosts</a>, allowing <a>shadow hosts</a> to selectively expose chosen elements from their <a>shadow tree</a> to the outside page for styling purposes.
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