add: new lake, file_name implementation

README.md

app/lib/widgets/graph_data/bar_data.dart

app/lib/widgets/main_layout.dart

app/lib/widgets/stat_charts.dart

images/geojson-export.png

images/geojson-file.png

images/overpass-query.png

images/resulting-files.png

server/main.py

server/map_handler/__pycache__/add_lake.cpython-311.pyc

.../map_handler/__pycache__/get_measurements.cpython-311.pyc

server/map_handler/add_lake.py

server/map_handler/get_measurements.py

server/map_handler/lake_relations/all_lake_names.json

server/map_handler/lake_relations/skumsjøen.geojson

server/map_handler/lake_relations/skumsjøen_centers.txt

server/map_handler/lake_relations/skumsjøen_div.json