Consider switching to a (new) copier-based template

[dalito]

I have recently worked with copier. It would allow a better user experience over the vocabulary-project´s lifecycle than the current solution.

Updating the vocabulary with changes made to the template would be improved. The number of conflicts can be kept much smaller (typically zero).

Another advantage is that the template can be documented independently from a project created from the template. For example, both can have independent README.md files at their root, which is not possible with the current template and typically causes conflicts when updating the project with latest changes from the template.

This issue has low priority as long as there are not more vocabularies based on this template. Moreover, #74 has further decreased the likelihood of conflicts.