Update news.json

assets/javascripts/news.json

@@ -1,4 +1,8 @@
 [
+  [
+    "2020-12-23",
+    "New documentation: <a href=\"/gtk/\">GTK</a>"
+  ],
   [
     "2020-12-07",
     "New documentations: <a href=\"/flask/\">Flask</a>, <a href=\"/groovy/\">Groovy</a>, <a href=\"/jinja/\">Jinja</a>, <a href=\"/werkzeug/\">Werkzeug</a>"