Document the columns input to CoCiP to skip certain model steps (aircraft performance, emissions)

[mlshapiro]

Description

For the CoCiP model, when a user provides input flight data with specific columns we skip the aircraft performance or emission modeling.

We should document this in:

• Cocip docstring
• CoCiP Notebook

The required Aicraft performance variables are: "wingspan", "engine_efficiency", "fuel_flow", "aircraft_mass"

The require Emission variables are: ""nvpm_ei_n""

Additional context

The same is done for meteorology in all the models, so we could also document in issr, sac, pcr, but this feels less pressing.