Pico C SDK: Missing documentation for `struct pio_program`

[pipatron]

I wanted to move from pioasm to generating my PIO programs directly in C code using the functions from pio_instructions.

pioasm generates a program in the form of a struct pio_program, necessary for use with various functions such as pio_add_program().

I could not find any documentation for this structure, even though it is a common parameter for a lot of functions in the SDK. It looks simple, but apparently it has been extended for the new PIO version 1, and I'm not quite sure how to use it. Would be great if this was documented.