Feat: validate domains are alive (and w/ CI)

Build/mod.d.ts

@@ -0,0 +1,22 @@
+import 'dns2';
+
+declare module 'dns2' {
+  import DNS from 'dns2';
+
+  declare namespace DNS {
+    interface DoHClientOption {
+      /** @example dns.google.com */
+      dns: string,
+      /** @description whether to use HTTP or HTTPS */
+      http: boolean
+    }
+
+    export type DnsResolver<T = DnsResponse> = (name: string, type: PacketQuestion) => Promise<T>;
+
+    declare function DOHClient(opt: DoHClientOption): DnsResolver;
+
+    export type $DnsResponse = DnsResponse;
+  }
+
+  export = DNS;
+}