PSn00bSDK changelog

05-23-2019 by Lameguy64:

* Added dev notes.txt file in docs that includes notes about the many
  quirks discovered about the system throughout the development of this SDK.

* Updated libn00bref.odf a little.

* Added rgb24 example.

* Made stack usage in ResetGraph() less wasteful.

* VSync IRQ handling now done using a custom exit handler. Actual VSync
  handling is yet to be moved to the custom exit handler though.

* Made stack usage in start.s of libc a lot less wasteful.

* Implemented controller support via BIOS functions (use _InitPad(),
  _StartPad() and _StopPad()). BIOS memory card functions may also
  work as well but its not tested yet.

* Removed duplicate initpad.s and initcard.s functions in psxapi.

* Added _InitCd() function to psxapi which is a safer version of _96_init()
  as it preserves other DMA channel settings. Use BIOS file functions such
  as open(), read() and close() with path names starting with cdrom:/ to
  access files from CD after calling _InitCd().