Rename css-anchor-1 to css-anchor-position-1 per WG resolution

Author: Peter Linss

css-anchor-1/Overview.bs renamed to css-anchor-position-1/Overview.bs

@@ -1,11 +1,11 @@
 <pre class='metadata'>
 Title: CSS Anchor Positioning
-Shortname: css-anchor
+Shortname: css-anchor-position
 Level: 1
 Status: ED
 Group: csswg
 Work Status: exploring
-ED: https://drafts.csswg.org/css-anchor-1/
+ED: https://drafts.csswg.org/css-anchor-position-1/
 Editor: Tab Atkins-Bittner, Google, http://xanthir.com/contact/, w3cid 42199
 Editor: Jhey Tompkins, Google, https://twitter.com/jh3yy, w3cid 137616
 Editor: Ian Kilpatrick, Google