added library compiler

[Yotona]

Rough proof-of-concept, very likely a much better way to handle building. Still uncertain if this is the exact ee-gcc build used to compile the library, others available through decomp.me also match the tested functions.

[Yotona]

I added a few bits of documentation adapted from the reference manuals. There was an issue with one define in sifdev.h that blocked it compiling, seems likely to be an issue with the includes being passed into the library compiler but I could not resolve it, weirdly it worked fine if that line was commented out.