[css-scroll-anchoring-1] Add trailing slash to ED URL

Rationale:

1. This is consistent with all other CSS drafts
2. This saves a redirect

Author: tidoust

css-scroll-anchoring-1/Overview.bs

@@ -5,7 +5,7 @@ Level: 1
 Group: csswg
 Status: ED
 Work Status: Revising
-ED: https://drafts.csswg.org/css-scroll-anchoring
+ED: https://drafts.csswg.org/css-scroll-anchoring/
 TR: https://www.w3.org/TR/css-scroll-anchoring-1/
 Previous Version: https://www.w3.org/TR/2020/WD-css-scroll-anchoring-1-20200211/
 Editor: Steve Kobes, Google
@@ -342,4 +342,4 @@ Changes</h2>
 Changes Since the Feb 11 2020 Working Draft</h3>
 
 	* Added definitions of [=viable candidate=] and [=priority candidate=].
-	* Clarified interaction between scroll anchoring and [=scroll snapping=].
+	* Clarified interaction between scroll anchoring and [=scroll snapping=].