Docstrings for modules are missing

[smartie2076]

We have to write docstrings for our modules, so that readthedocs can help users or new programmers.

To keep track of the modules that need docstrings:

• [x] A0_initialization.py
• [ ] A1_csv_to_json.py - missing conversion()
• [x] B0_data_input_json.py :x: B2_read_csv.py
• [ ] C0_data_processing.py - docstrings could use some more information (about parameters, one line explaining what the function does)
• [x] C1_verification.py
• [x] C2_economic_functions.py
• [x] D0_modelling_and_optimization.py
• [x] D1_model_components.py
• [x] D2_model_constraints.py
• [x] E0_evaluation.py - could be more complete
• [x] E1_process_results.py
• [ ] E2_economics.py - write all docstrings
• [x] E3_indicator_calculation.py
• [x] E4_verification_of_constraints.py
• [x] F0_output.py
• [ ] F1_plotting.py - update group_costs(), check draw_graph()
• [ ] F2_autoreport.py - add parameter descriptions

[smartie2076]

@Bachibouzouk, @SabineHaas, @ursulaelmir please keep in mind to update the list if a module is completely commented out with docstrings.

[SabineHaas]

I started to write docstrings when writing the test function names. Started for C1 in #152. I think this makes sense as I need to understand the functionality for testing - so I can also add a docstring :)

[SabineHaas]

I checked the boxes of the modules that do have docstrings already. And wrote some todos behind the boxes I didn't check. Feel free to add your names to the modules you write docstrings for and check the boxes once you're done :)

[smartie2076]

We should check the progress on this task.