ESS copier template

[SimonHeybrock]

We are planning to make technique-specific or instrument-specific repositories instead of dumping everything into scipp/ess. The recently added https://github.com/scipp/copier_template will simplify a lot of the project setup. However, there will likely be ESS-specific project config (such as dependency, test setup, docs theming, ...) that we would not want to add to the generic scipp/copier_template.

According to the copier docs is it possible to apply multiple templates to the same repository.

• Look into whether our ESS-projects needs are orthogonal to those from the generic scipp/copier_template.
• If so, setup such a template.

[jokasimr]

The ESS-specific project config is in progress here

[SimonHeybrock]

Closing, since by now we have https://github.com/scipp/ess_template (albeit quite empty).