More comprehensive continuum for climate model, by default

[Nicholaswogan]

Currently, when calling opannection with method='resortrebin', the default continuum file is reference/climate_INPUTS/ck_cx_cont_opacities_661.db. I think this file only contains H2-H2, H2-H2, H2-H, H2-CH4 and H2-N2 CIA partners. For more exotic gas-rich atmospheres with very high metallicities (e.g., GJ 1214 b), which might have a lot of CO2 or H2O, then perhaps other CIA become important like CO2-CO2, H2O-H2O, etc. I imagine they would have a big impact on the deep-atmosphere opacity.

I have gathered a pretty comprehensive set of CIAs here in regular grids: https://github.com/Nicholaswogan/photochem_clima_data/tree/main/photochem_clima_data/data/CIA . Maybe, by default, PICASO should include some of these CIAs, to improve flexibility of the model.