swagger docs

1. fastify swagger

1. install

   pnpm add @fastify/swagger @fastify/swagger-ui
   

2. add to src/index.ts

   import swagger from '@fastify/swagger';
   import swaggerUI from '@fastify/swagger-ui';
   
   await fastify.register(swagger, {
     openapi: {
       info: {
         title: 'Fastify API',
         description: 'Fastify + Swagger',
         version: '1.0.0',
       },
     },
   });
   
   await fastify.register(swaggerUI, {
     routePrefix: '/docs',
   });