RDP Triangle Command Guide

[kev4cards]

This document link was posted recently on the N64Brew (N64 development and homebrew) discord server: https://docs.google.com/document/d/17ddEo61V0suXbSkKP5mY97QxgUnB-QfAjuBIsPiLWko/edit . I figure this could be helpful for squashing the remaining bugs in GlideN64's LLE implementation. That said, I have not personally verified the document (not familiar with author, either) to be accurate, but other accuracy-minded individuals within the community seem to think it is good.