[BUG] Missing documentation for some namespaces.

[tvoigtlaender]

Missing namespaces in documentation
Some namespaces in the CROWNlib are missing entries in the readthedocs documentation.
The following namespaces have a broken or missing readthedocs site:

• Basefunctions
• Correctionmanager
• Onnxhelper
• Utility
• fmt

Other notes
This might be connected to the use of templates.
The cmake code used to generate the html files locally is also quite old.