Recommend and initialize a custom user model

[silviogutierrez]

The vast majority of projects require authentication and custom fields. And it's much easier to set this up when starting a project than later on.

Should we initialize new Reactivated projects with core/models.py and User model set up?

Background reading:

• https://docs.djangoproject.com/en/4.0/topics/auth/customizing/#substituting-a-custom-user-model
• https://docs.djangoproject.com/en/4.0/topics/auth/customizing/#a-full-example
• https://dev.to/chokshiroshan/how-to-use-email-as-username-for-django-authentication-8if

More thoughts

This will also allow is to provide The Way™ to customize the HttpRequest mypy stub to hold a custom user type, which is often needed when using typed Django.