An overhaul of my original PlayStation bare-metal programming tutorial repo: https://github.com/spicyjpeg/ps1-bare-metal

It was never really meant to be an SDK of sorts that other PS1 homebrew projects would pull as a submodule and depend on, but since it more or less became one I am likely going to split off the examples from the "core" (headers, CMake build scripts and tools). I have also been asked to add more examples, particularly on how to play sounds through the SPU and access the CD-ROM drive, and may cover I/O on some PS1-based arcade systems in the future.