Adjust the code to be consistent with django documentation

Prerequisite

• We are using Django Version 4.1
• We are using the documentation for that version: https://docs.djangoproject.com/en/4.1/

Description

• The current implementation slightly differs from the django documentation
• This should be changed for a better code reading, improved maintainability and easier feature implementation

Steps to do

• project structure (directory structure) should be revised
  • seems to be correct
• urls revised
  • e.g. an application should provide its own urls.py which can be included in the
• consistent naming
  • e.g. in tsm/apps.py: MainConfig should be named TsmConfig
• --add additional points before implementing them--

Definition of done