* prepare_sector_network:
- add link for oil boiler in function add_industry()
- add function for partitioning clusters into different heat node types
* config.yaml: add option for oil_boiler
* costs.csv: add costs for oil boiler
These are different for residential and services demand.
Also include Snakefile in config files copied for each run.
Use gurobi settings from gurobi support for speed.
Commented out settings for testing randomness for noise.
These are specified in data/heat_load_profile.csv.
The resulting heat_demand df has MultiIndex columns, where the first
level is ["sector use"], and the second level level is nodes.