Template files try to overwrite on copier update

[eckelsjd]

Desired

• When running copier update, local files like README, .github actions, etc. that have changed since copier init should not be overwritten by the original copier template
• On copier update, we should only update files that have changed in the copier template, not try to reset all local files that are different from the copier template.

Actual

• Copier update makes a ton of merge conflicts in the local files that are different from the copier template