link a trial GH issue

Author: svgeesus

css-color/Overview.bs

@@ -11,6 +11,7 @@ Editor: Tab Atkins Jr., Google, http://xanthir.com/contact
 Editor: Chris Lilley, W3C, chris@w3.org
 Former Editor: L. David Baron, Mozilla Corporation, dbaron@dbaron.org
 Abstract: This specification describes CSS <<color>> values and properties for foreground color and group opacity.
+Repository: w3c/csswg-drafts
 Inline Github Issue Titles: true
 Ignored Terms: stacking context, double, octet, DOMString
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