* use doxygen
* add documenting guide based on https://github.com/zeldaret/oot/blob/main/docs/Documenting.md
* exclude stdlib readme from doxygen
* refuse to configure matching iQue on macOS (EGCS compiler is not built for macOS, so iQue won't build. We still enable iQue builds on macOS by using gcc-papermario via --non-matching.)
* use proper doxygen bug comment style
* document common EVT API funcs nicely
* add doxygen ci
* add \vars command
