Although I do not think that we can create southern migrations without creating a real django site (by the way, you also need a django site for testing). Just process your package like other django packages and run schemamigration <your_app_name>to create migrations for it.
You only need to allow the migration of the django repository in the package migration folder instead of "env / lib / pythonXX / site-packages /". You need to install the application using pip editable . "
pip install -e local_path/to/your_package