docs(who-uses): add tarken.ag

Author: micalevisk

content/discover/who-uses.json

@@ -271,6 +271,7 @@
     "https://swyftlogistics.com",
     "https://evershop.io",
     "https://e-design.ca",
-    "https://growthmill.com"
+    "https://growthmill.com",
+    "https://tarken.com.br"
   ]
 }