Class documentation for Pydantic configs.

[braceal]

Each pydantic data class should have documentation on each parameter. It will also be very important to document the exceptions validation can raise so users know how to set the parameters.

To do this, after each property in the pydantic class, add a """_description_""" block. For example:

class MyConfig(BaseSettings):
    """Configuration for ..."""
    
    output_path: Path
    """Path to write output files to."""