Added py_package. environment and gitignore

.gitignore

env.yml

py_package/pyproject.toml

py_package/src/entfrachten/__init__.py

py_package/src/entfrachten/analysis/__init__.py

...age/src/entfrachten/analysis/cross_section_info_loader.py

py_package/src/entfrachten/analysis/drainage_system_graph.py

py_package/src/entfrachten/analysis/drainage_sysytem_data.py

py_package/src/entfrachten/analysis/dynamic_analysis.py

py_package/src/entfrachten/analysis/sewer_map.py

py_package/src/entfrachten/analysis/simulation_reading.py

py_package/src/entfrachten/analysis/static_analysis.py

py_package/src/entfrachten/analysis/unit_factors.py

py_package/src/entfrachten/optim/__init__.py

py_package/src/entfrachten/optim/loss_functions.py

py_package/src/entfrachten/optim/optim_dumper.py

py_package/src/entfrachten/optim/simulation.py

py_package/src/entfrachten/optim/simulation_dummy.py

py_package/src/entfrachten/plotting/struct_plot.py