Support user configs

[browniebroke]

Is your feature request related to a problem? Please describe.

Copier recently added support for user defined configs, where one can set some "global" variables in a config file to pre-fill them when running a template. They suggest a few "well-known" variables which this template should try to adopt: https://copier.readthedocs.io/en/latest/settings/#well-known-variables

That will probably end up being a breaking change for the template as the inputs will change and will prevent folks to run copier update.

Describe alternatives you've considered

n/a

Additional context

PR: copier-org/copier#1940

Documentation: https://copier.readthedocs.io/en/latest/settings/