Addes ping method

backend/src/app.controller.ts

@@ -0,0 +1,12 @@
+import { Controller, Get } from '@nestjs/common';
+import { ApiOperation, ApiTags } from '@nestjs/swagger';
+
+@ApiTags('App')
+@Controller()
+export class AppController {
+    @ApiOperation({ description: 'check site availability' })
+    @Get('ping')
+    pingpong() {
+        return 'pong';
+    }
+}