Describe PFSS field line behaviour for reference point #87
Description
The behaviour of PFSS field lines for an optional reference point needs to be described because they behave a little bit different given that we perform an upward tracing which can lead to closed field lines!
This needs to be done at the following points:
- https://solarmach.readthedocs.io/en/latest/usage.html#9.-Further-backmapping-with-PFSS
- https://solarmach.readthedocs.io/en/latest/api.html#solarmach.SolarMACH.plot_pfss
- https://solarmach.readthedocs.io/en/latest/api.html#solarmach.SolarMACH.plot_pfss_3d (or pfss_3d for older version)
- Solar-MACH streamlit version