Set up Amplify to work with multiple developers

Because this is a collaborative project, we need to make sure that multiple people can work on the code. It seems that Amplify gets kind of funky with multiple developers, and managing "group" (IAM) AWS seems tricky (though still worthwhile to learn).

It seems one of the better ways to do this is to use separate AWS accounts, but the same frontend code. One issue that arises with this approach is that different developers are working with different operations. I think the solution to this is to have each "dev" user have a different homepage, or more simply for now have different developer tabs that show up.

Also nice to not have to worry about others incurring costs.

- [Amplify Auth](https://docs.amplify.aws/cli/auth/groups/) - User Groups