Simplify templates

[Kaliumhexacyanoferrat]

In times of agentic coding, project templates are no longer important for the end users, as the agents will generate the project for them and add functionality as needed.

Therefore, remove the strong emphasis on templates on the readme and the documentation but keep a single, simple template to showcase the typical project structure and usage of modules. Link the templates from the readme with that hint.

[Kaliumhexacyanoferrat]

Templates will be dropped in total - and replaced by samples in the main project.