Create feature_lookups.py

Create node_features.py

Create __init__.py

Rename src/build_geographical_edges.py to src/data_prep/build_geographical_edges.py

Rename src/build_lobbying_events.py to src/data_prep/build_lobbying_events.py

Rename src/build_campaign_events.py to src/data_prep/build_campaign_events.py