Since it's a shader collection, there is not much of a documentation to add, you can find the details in the first page, and if you buy the pack, you'll find a "WELCOME" text in the text editor which gives information on how the shaders were designed!

CHANGELOG:
    _v1.1:
        -22/06/2020 (Blender 2.82a)
        -huge optimisation on the file itself, it went from 25 MB to 6 MB
        -changed name to "Blender Automotive Procedural Shaders"
        -added version number on nodes not to mess up with the node groups between the updates
        -NEW SHADER:
                 -introducing a tire shader
        -Carbon Fiber:
                 -completely redesigned light behaviour
                 -removed bump node to do the normal mixing by hand instead, way cleaner
                 -removed the ambient occlusion node... it was supposed to give better contrast in EEVEE but was a pain in interior visualisation
                 -"fiber strengh" parameter becomes "fiber curvature"
                 -when flat, the fiber has a way better look thanks to the generated normals
                 -removed some useless nodes
                 -in general this is cleaner, better, cooler
                 -(sensitve though with the fiber direction, be sure to have proper UVs or to do a cube projection even if you use Triplanar)
        -Carpaint:
                 -removed the ambient occlusion node
        -Brake Disc:
                 -less extreme and rusty
                 -added "incadescence" parameter if you want a 24h du Mans style
        -Alcantara:
                 -completely different, looks better with a wider range of colors than the previous one
        -Aluminium:
                 -removed the bump and use Normals instead... looks cleaner
        -Reflectors:
                 -completely new pattern, thanks to Macos Beltrao for the inputs
        -Triplanar node:
                 -supports now good projection on the backside of the three projection axis, necessary to respect tangent space for normal maps
       
       
    _v1.0:
        -28/05/2020 (Blender 2.82a)
        -first release