Add Vercel TXT record for domain verification

Adding the required TXT record for Vercel domain verification. 

This allows Vercel to verify ownership of yashwant.is-a.dev and issue SSL so the subdomain works correctly with the deployment.

domains/yashwant.json

@@ -6,6 +6,9 @@
     "email": "kumarkyashwant@gmail.com"
   },
   "records": {
-    "CNAME": "portfolio2-kappa-flame.vercel.app"
+    "CNAME": "portfolio2-kappa-flame.vercel.app",
+    "TXT": {
+      "_vercel": "vc-domain-verify=yashwant.is-a.dev,11b5c01be56a6a6d14ca"
+    }
   }
 }