docs(nestjs): add queue events listeners section

docs/gitbook/SUMMARY.md

@@ -43,6 +43,7 @@
 * [Architecture](guide/architecture.md)
 * [NestJs](guide/nestjs/README.md)
   * [Producers](guide/nestjs/producers.md)
+  * [Queue Events Listeners](guide/nestjs/queue-events-listeners.md)
 * [Going to production](guide/going-to-production.md)
 * [Migration to newer versions](guide/migration-to-newer-versions.md)
 

docs/gitbook/guide/nestjs/queue-events-listeners.md

@@ -0,0 +1,49 @@
+# Queue Events Listeners
+
+To register a QueueEvents instance, you need to use **QueueEventsListener** decorator:
+
+```typescript
+import {
+  QueueEventsListener,
+  QueueEventsHost,
+  OnQueueEvent,
+} from '@nestjs/bullmq';
+
+@QueueEventsListener('queueName')
+export class TestQueueEvents extends QueueEventsHost {
+  @OnQueueEvent('completed')
+  onCompleted({
+    jobId,
+  }: {
+    jobId: string;
+    returnvalue: string;
+    prev?: string;
+  }) {
+    // do some stuff
+  }
+}
+```
+
+And then register it as a provider:
+
+```typescript
+@Module({
+  imports: [
+    BullModule.registerQueue({
+      name: 'queueName',
+      connection: {
+        host: '0.0.0.0',
+        port: 6380,
+      },
+    }),
+  ],
+  providers: [TestQueueEvents],
+})
+export class AppModule {}
+```
+
+## Read more:
+
+- 💡 [Queues Technique](https://docs.nestjs.com/techniques/queues)
+- 💡 [Register Queue API Reference](https://nestjs.bullmq.pro/classes/BullModule.html#registerQueue)
+- 💡 [Queue Events Listener API Reference](https://api.docs.bullmq.io/interfaces/v4.QueueEventsListener.html)