update nest.js

Author: willin

basic/framework/nest.md

@@ -99,6 +99,33 @@ bootstrap();
 
 Module 代码可以参考 Express Swagger 的示例项目： <https://github.com/nestjs/nest/tree/master/sample/11-swagger>
 
+生成 Open-API.json 文件示例代码：
+
+```js
+import { resolve } from 'path';
+import { writeFileSync } from 'fs';
+
+import { NestFactory } from '@nestjs/core';
+import { FastifyAdapter, NestFastifyApplication } from '@nestjs/platform-fastify';
+import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
+import { AppModule } from './app.module';
+
+async function bootstrap() {
+  const app = await NestFactory.create<NestFastifyApplication>(AppModule, new FastifyAdapter());
+  const options = new DocumentBuilder()
+    .setTitle('Cats example')
+    .setDescription('The cats API description')
+    .setVersion('1.0')
+    .addTag('cats')
+    .addBearerAuth()
+    .build();
+  // 生成的 JSON 格式文档，可以导出静态化
+  const document = SwaggerModule.createDocument(app, options);
+  writeFileSync(resolve(__dirname, '../api.json'), JSON.stringify(document, null, 2), { encoding: 'utf8' });
+}
+bootstrap();
+```
+
 
 ## E2E Testing