Add Vercel configuration for domain verification

domains/_vercel.hori.json

@@ -0,0 +1,9 @@
+{
+    "owner": {
+        "username": "duckzangryy",
+        "email": "cutievanh@gmail.com"
+    },
+    "records": {
+        "TXT": "vc-domain-verify=hori.is-a.dev,f1ba1aecaad9123a1003"
+    }
+}