$ npm install
# development
$ npm run start
# watch mode
$ npm run start:dev
# production mode
$ npm run start:prod
GET, POST
http://localhost:3000/product
PUT, DELETE
http://localhost:3000/product/:id
GET BY CATEGORY
http://localhost:3000/product/by/category/:category
GET BY ID
http://localhost:3000/product/by/id/:id
{
"name": "string",
"category": "string",
"amount": "number"
}