configurar env vars https://stackoverflow.com/questions/63285055/nestjs-how-to-use-env-variables-in-main-app-module-file-for-database-connecti https://egghead.io/lessons/node-js-configure-a-nestjs-api-with-environment-variables-using-configmodule-and-joi https://codersera.com/blog/how-to-integrate-dotenv-with-nestjs-and-typeorm/ docs com swagger deploy no heroku https://www.joshmorony.com/deploying-a-production-nestjs-server-on-heroku/#2-modify-the-packagejson-file https://www.youtube.com/watch?v=cBIUOL6MFXw