release news for 2024-12-31

- announce version 2.3 of the mkiocccentry repo
- update `sitemap.xml`
- update `status.json` and `status.html`

status.json

@@ -2,6 +2,6 @@
     "no_comment" : "mandatory comment: because comments were removed from the original JSON spec",
     "IOCCC_status_version" : "1.0 2024-03-09",
     "contest_status" : "pending",
-    "news_update" : "2024-12-29T09:57:30+00:00",
+    "news_update" : "2024-12-31T21:39:37+00:00",
     "status_update" : "2024-12-29T10:01:35+00:00"
 }