As a user, I want to be able to register for an account easily. #3
Description
start with email for now, then implement others later.
with email: https://medium.com/flutterpub/flutter-how-to-do-user-login-with-firebase-a6af760b14d5
with google: https://pub.dev/packages/google_sign_in
with facebook: https://pub.dev/packages/flutter_facebook_login
with phone number: https://medium.com/@jackwong_60367/sms-code-authentication-in-flutter-23d5071e084b
or
https://medium.com/flutter-community/firebase-phone-authentication-on-a-flutter-app-78104686efc5