Missing documentation: Common Hardware

[boustanihani]

Could you please provide some documentation about using scripts under common:
https://github.com/NixOS/nixos-hardware/tree/master/common

It is not clear how multiple common configs should be imported, if the laptop model is not listed..
Like for example, how should my config look like, if I have a "noname" laptop, with intel and nvidia, and I want to activate all intel features and say disable the nvidia card completely. And what should I change to enable "Optimus PRIME" or maybe work with nvidia only..

Some examples with and without using Home Manager would be great.