camb_pk_interp passed to ArinyoModel needs special attributes attached #43
Description
When calling the ArinyoModel with a passed-in camb_pk_interp, it has to not only be an interpolator function but must have some additional attributes, such as camb_kmax_Mpc:
arinyo = ArinyoModel(cosmo_dict, camb_pk_interp=some_pk_interp_function_with_attributes)
If those attributes aren't attached, it can cause errors. We should specify this directly in the docs or make this simpler for the user.