changed docker file nest to avoid rebuild everything each time, and small changes in chat gateway

tests_hugo/nest_course/dist/app.controller.d.ts

@@ -0,0 +1,6 @@
+import { AppService } from './app.service';
+export declare class AppController {
+    private readonly appService;
+    constructor(appService: AppService);
+    getHello(): string;
+}