docs(websockets): update for extend socket.io

Author: Tony133

content/websockets/adapter.md

@@ -30,21 +30,21 @@ The WebSockets module is platform-agnostic, hence, you can bring your own librar
 The [socket.io](https://github.com/socketio/socket.io) package is wrapped in an `IoAdapter` class. What if you would like to enhance the basic functionality of the adapter? For instance, your technical requirements require a capability to broadcast events across multiple load-balanced instances of your web service. For this, you can extend `IoAdapter` and override a single method which responsibility is to instantiate new socket.io servers. But first of all, let's install the required package.
 
 ```bash
-$ npm i --save socket.io-redis
+$ npm i --save @socket.io/redis-adapter
 ```
 
 Once the package is installed, we can create a `RedisIoAdapter` class.
 
 ```typescript
 import { IoAdapter } from '@nestjs/platform-socket.io';
-import { RedisClient } from 'redis';
-import { ServerOptions } from 'socket.io';
-import { createAdapter } from 'socket.io-redis';
+import { Server, ServerOptions } from 'socket.io';
+import { createAdapter } from '@socket.io/redis-adapter';
+import { createClient } from 'redis';
 
-const pubClient = new RedisClient({ host: 'localhost', port: 6379 });
+const io = new Server();
+const pubClient = createClient({ url: `redis://localhost:6379` });
 const subClient = pubClient.duplicate();
-const redisAdapter = createAdapter({ pubClient, subClient });
-
+const redisAdapter = io.adapter(createAdapter(pubClient, subClient));
 export class RedisIoAdapter extends IoAdapter {
   createIOServer(port: number, options?: ServerOptions): any {
     const server = super.createIOServer(port, options);