Add code documentation

example/example_simulation.ipynb

example/frontend_interface.ipynb

example/pafsim_config.json

pafsim/chain.py

pafsim/connector.py

pafsim/executor.py

pafsim/processor/__init__.py

pafsim/processor/_processor.py

pafsim/processor/beamformer.py

pafsim/processor/calibrator.py

pafsim/processor/channelizer.py

pafsim/processor/correlator.py

pafsim/processor/generator.py

pafsim/processor/waveform.py

pafsim/vector.py

pyproject.toml

scripts/create_datasets.py

scripts/simulate_dataset.py