Add Vercel TXT verification

domains/_vercel.karthikeshwar.json

@@ -0,0 +1,9 @@
+{
+  "owner": {
+    "username": "KarthikeshwarAnanthapur",
+    "email": "karthikeshwarananthapur@gmail.com"
+  },
+  "record": {
+    "TXT": "vc-domain-verify=karthikeshwar.is-a.dev,1f8e3d8772df5bacb88c"
+  }
+}