feat: register gaganjain.is-a.dev and www.gaganjain.is-a.dev for Vercel

- gaganjain.is-a.dev -> CNAME cname.vercel-dns.com (Vercel universal target)
- www.gaganjain.is-a.dev -> CNAME cname.vercel-dns.com
Vercel custom-domain verification via CNAME (standard is-a.dev pattern).

domains/gaganjain.json

@@ -0,0 +1,8 @@
+{
+  "owner": {
+    "username": "gaganjainse"
+  },
+  "records": {
+    "CNAME": "cname.vercel-dns.com"
+  }
+}

domains/www.gaganjain.json

@@ -0,0 +1,8 @@
+{
+  "owner": {
+    "username": "gaganjainse"
+  },
+  "records": {
+    "CNAME": "cname.vercel-dns.com"
+  }
+}