Add Vercel domain configuration for verification

domains/_vercel.andygu.json

@@ -0,0 +1,9 @@
+{
+    "owner": {
+        "username": "guabao08",
+        "email": "andy.gu@duke.edu"
+    },
+    "records": {
+        "TXT": "vc-domain-verify=andygu.is-a.dev,2a31c74d1c41b7e9236e"
+    }
+}