Add Vercel TXT ownership verification for jithesh-gopinathan

Vercel reported the domain as linked to another account and requires
a TXT record at _vercel.jithesh-gopinathan.is-a.dev to verify
ownership before it can be connected to this project. Adds that
record following the same pattern used by other is-a.dev domains
that hit this same Vercel verification requirement.

domains/_vercel.jithesh-gopinathan.json

@@ -0,0 +1,13 @@
+{
+  "name": "_vercel.jithesh-gopinathan",
+  "description": "Vercel TXT ownership verification",
+  "owner": {
+    "username": "jitheshlive",
+    "email": "jitheshlive@gmail.com"
+  },
+  "records": {
+    "TXT": [
+      "vc-domain-verify=jithesh-gopinathan.is-a.dev,8ccd018398d1a54f97ef"
+    ]
+  }
+}