I worked further on the source code of the Plone add-on collective.templates and added a feature to display the username and the e-mail address of a project owner on his/her choice. The new release contains also an improved user documentation.
You could download the new release from the Cheeseshop (https://pypi.org):
https://pypi.org/project/collective.templates/
The source code is available from the Github repository of the Plone collective:
https://github.com/collective/collective.templates