docs: add more setup guide

README.md

@@ -18,6 +18,13 @@ AUTH_KEY="asdfasdasddfasdfasddf"
 CHAT_ID=""
 ```
 
+to get the chat id, add the following code to `src/index.ts` (under the qr code listener) and run it locally. then send a message to the chat you want to send notifs to:  
+```ts
+wa.on("message_create", (message) => {
+  console.log(`[WA] the chat id for the message you sent is: ${message.to}`);
+})
+```
+
 ```bash
 bun run src/index.ts
 ```