Project update

[jonra1993]

Thanks for this fast API setup. In this Pull request, I have added some suggestions on issues

1. nullable=False on id to avoid problems on migrations
2. settings file
3. db file upgrade
4. readme add how to make migrations with alembic

[mjhea0]

Thanks. Since the project is tied to a tutorial -- https://testdriven.io/blog/fastapi-sqlmodel/ -- the code and tutorial need to be updated at the same time. I should have some time later this month to look at this.

[mjhea0]

Apologies for the delay, @jonra1993. It's really difficult to accept PRs from folks who are not also updating the tutorial at the same time. @amirtds and I updated both. We captured most of your changes. If you still want to contribute, please address the merge conflicts. Thank you!