added cname for my subdomain

domains/pratham.json

@@ -0,0 +1,9 @@
+{
+  "owner": {
+    "username": "Prathamdas3",
+    "email": "daspratham3@gmail.com"
+  },
+  "record": {
+    "CNAME": "prathamdas.vercel.app"
+  }
+}