Add some documentation to describe the proposed model for cross-compilation, associated flags, and the reasoning for the structure. This should allow us to have a reference for the design allowing us to evolve the model.
Co-authored-by: Evan Wilde <ewilde@apple.com>
Co-authored-by: Alexander Smarus <bender@readdle.com>
Co-authored-by: Danielle <dani@builds.terrible.systems>
