[scroll-animations-1] Update use cases link to point to csswg-drafts repository copy

Author: birtles

scroll-animations-1/Overview.bs

@@ -93,7 +93,7 @@ For readability they have not been repeated explicitly.
 <em>This section is non-normative</em>
 
 Note: Based on this <a
-href="https://github.com/WICG/scroll-animations/blob/master/Use%20cases.md">curated
+href="https://github.com/w3c/csswg-drafts/blob/master/scroll-animations-1/Use%20cases.md">curated
 list of use cases</a>.