added connection to the dataBase

src/main.ts

@@ -1,8 +1,11 @@
 import { NestFactory } from '@nestjs/core';
 import { AppModule } from './app.module';
+import { ValidationPipe } from '@nestjs/common';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
+  app.useGlobalPipes(new ValidationPipe());
+  app.enableCors();
   await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();