(see: https://thecodebee.com/fake-api-for-angular-2+-during-development-using-angularcli/)

• yarn global add json-server
• yarn add --dev json-server
• Create a proxy file proxy.conf.json
• edit package.json => "start": "ng serve --proxy-config proxy.conf.json",

Run: // @TODO: move to Firebase as json-server makes the page reload after submitting a form

• json-server --watch "src/assets/db.json"
• yarn start