Add missing "tw" entry in flags.json for tw.svg (#2217)

Co-authored-by: Paweł Kuna <1282324+codecalm@users.noreply.github.com>
Co-authored-by: codecalm <codecalm@gmail.com>

preview/pages/_data/flags.json

@@ -915,6 +915,10 @@
     "name": "Tuvalu",
     "flag": "tv"
   },
+  {
+    "name": "Taiwan",
+    "flag": "tw"
+  },
   {
     "name": "Tanzania",
     "flag": "tz"
@@ -995,4 +999,4 @@
     "name": "Zimbabwe",
     "flag": "zw"
   }
-]
+]