feat: register nested subdomain

domains/apps.zen.json

@@ -0,0 +1,9 @@
+{
+  "owner": {
+    "username": "zen-geohub",
+    "email": "abidinzaenal556@gmail.com"
+  },
+  "records": {
+    "A": ["3.81.229.169"]
+  }
+}