fix: Create data_dir if it does not exist

src/dns.rs

@@ -267,6 +267,9 @@ async fn init_dns_registrations(
 async fn write_registrations(registrations: &Registrations, config: &Config) {
     let path = config.data_dir.join("registrations.toml");
     let contents = toml::to_string(registrations).unwrap();
+    if !config.data_dir.exists() {
+        tokio::fs::create_dir_all(&config.data_dir).await.unwrap();
+    }
     tokio::fs::write(path, contents).await.unwrap();
 }