Regarding materials and shaders we encourage you to watch this tutorial video.
The tutorial explains the basics of working with and creating 3D environments in Aximmetry.

https://youtu.be/ORANezf5Q9o?t=418

For more advanced tutorials please find more videos relating to this topic on this playlist:

https://www.youtube.com/playlist?list=PLUCy1LBtG-_sAU7ACN1w6icST6LNIu0ql

Also read through this pdf for further details:

https://aximmetry.hu/en/documentation/Manuals/Shader%20Categories%20and%20Naming%20Convention.pdf 

Also note that Aximmetry only works with its own shader system.

I didn't understand the last part,

did you mean that users don't have to build shaders in aximmetry but only use ready to use shaders?

I mean new  -) shader workflow

Sorry, it seems we misunderstood your question.
You're asking about creating your own custom shaders.

Normally users do not have to do that since you have lots of ready made shader combinations for any use cases.
You only need to modify any shader in very specific cases.

In that sense, we do not recommend for beginners to deal with the shader system.

However, for advanced users we have a documentation on the basics:
https://aximmetry.com/en/documentation/Manuals/Creating%20New%20Shaders.pdf

Are there any other documents about this topic other than this file?

So far this is the only one.
In practice you always start from an existing shader when you create a new one and only modify a few things.