tailwindcss: add news entry

assets/javascripts/news.json

@@ -1,6 +1,10 @@
 [
   [
-    "2021-01-12",
+    "2022-02-21",
+    "New documentation: <a href=\"/tailwindcss/\">Tailwind CSS</a>"
+  ],
+  [
+    "2022-01-12",
     "New documentation: <a href=\"/react_router/\">React Router</a>"
   ],
   [