[css-values-4] update metadata

Author: fantasai

css-values-4/Overview.bs

@@ -5,8 +5,8 @@ Shortname: css-values
 Level: 4
 Status: ED
 Work Status: Exploring
-ED: https://drafts.csswg.org/css-values/
-TR: https://www.w3.org/TR/css-values/
+ED: https://drafts.csswg.org/css-values-4/
+TR: https://www.w3.org/TR/css-values-4/
 Previous version: https://www.w3.org/TR/2018/WD-css-values-4-20180814/
 Editor: Tab Atkins, Google, http://xanthir.com/contact/, w3cid 42199
 Editor: fantasai, http://fantasai.inkedblade.net/contact, w3cid 35400