[css-font-display] mark as UD, and replaced by Fonts 4.

css-font-display/index.bs

@@ -1,12 +1,15 @@
 <pre class='metadata'>
 Title: CSS Font Display Controls Module Level 1
 Status: UD
+Group: CSSWG
+Work Status: abandoned
 Shortname: css-font-display
 Level: 1
 Editor: Tab Atkins, Google, http://xanthir.com
 Editor: Kenji Baheux, Google
 Abstract: This spec introduces a new ''@font-face'' descriptor for controlling how a downloadable font renders before it is fully loaded.  It's intended that this spec be merged into the Fonts spec, likely Fonts Level 4.
 ED: https://tabatkins.github.io/specs/css-font-display/
+Warning: replaced by https://drafts.csswg.org/css-fonts-4/#font-display-desc
 </pre>
 
 Introduction {#intro}