This whole package was built initially in v2.82 and about half way through, I switched to v2.93. As it's all default Blender nodes being used, all of the shaders will work in anything from 2.82 and above. It'll likely work with older versions, though I can't guarantee it. 

There's a manual in the downloads which just introduces a couple of general rules that apply to all of the shaders and a library of all the materials.