feat: add _vercel.phucbao.json for domain verification

domains/_vercel.phucbao.json

@@ -0,0 +1,11 @@
+{
+  "owner": {
+    "username": "tdbaophuc",
+    "email": "tdbaophuc@gmail.com"
+  },
+  "records": {
+    "TXT": [
+      "vc-domain-verify=phucbao.is-a.dev,95ea8ce6dc81fa6acda2"
+    ]
+  }
+}