Extract household code and data

[MichaelBoegl]

Related to #3 extract household code and data

[MichaelBoegl]

Available household data (with appropriate license): https://data.open-power-system-data.org/household_data/
Explanation of the data: https://nbviewer.org/github/isc-konstanz/household_data/blob/2020-04-15/main.ipynb