Switch to copier

[ibizaman]

Currently, the UX is sub-par because the user must go through each file and generate stuff manually.

We could create an ad-hoc bash script to generate what needs to be generated but why reinvent the wheel.

If using copier instead of flake templates, initializing the template will prompt the user for questions so the template gets generated with their answers directly. One can even later make changes to the repo and then apply updates from the template and things get merged.