Can we use a value of center that is outside of the domain? E.g. if we want to model a shell with a pointmass, can the value of center be at the origin, but ymin be at some large positive value?

🎯 Describe what you'd like

Currently the option isotope="all" is only available in user defined (saved) databank but not when fetching a databank (for example hitran); it raises the error ValueError: Please define isotope explicitely (cannot use 'all' with fetch_databank)

The goal is simple: make the option isotope="a

We already have some Jupyter Notebooks, but we could aggregate them all (and more examples #1 ) in a single file, as done in the excellent EinsteinPy project 👍
https://hub.gke.mybinder.org/user/einsteinpy-einsteinpy-od42vu7m/notebooks/index.ipynb