API reference documentation inaccurate

[samiransen23]

1. Several API reference documentations of HyMD have been naïvely copied or left unchanged though the functions are different.
2. Some parameters are part of a list, while others are list of lists. Python documentation loosely suggests to care about the dimensionality only for numpy arrays but I'd rather avoid confusion by being explicit.
   Example: phi : list[pmesh.pm.RealField] but phi_fourier :list[ list[pmesh.pm.ComplexField], 3] and not phi_fourier : list[pmesh.pm.ComplexField]

[hmcezar]

Good point, we should definitely check and make the documentation consistent with the actual objects.