I've been trying to learn to use json formatting in list columns, views and forms, but struggling. I look at a LOT of samples over at github, thinking I can use them as a guide to understand the structure. I also spend a lot of time with the "Formatting syntax reference". These have been helpful, but what's really frustrating is that I can't seem to find any resources that list out details like class definitions, valid styles for different elmTypes, etc. Basically, the only way to know what classes are available and what impact they have on a rendering is to borrow them from one the samples. Trial and error is not the most efficient way to learn this stuff.
