A guide to working with RivalTheory Rain behavior trees [warning: gigantic]

This, I believe, is the longest bit of documentation I've ever written in a single go. All told it's 52 pages. My goal with this guide was to give a truly useful overview of Rain for absolute beginners. Learning to use Rain was supremely difficult for me in the beginning, and a big reason was due to the fact that there was very little documentation out there. I'm particularly proud of this one because the vast majority of it came from my own trial and error.