Adds special settings for AMD models. linuxPackages 5.8 is currently only available in 20.09, but is required for backlight and microphone to work. The graphics chipset should work with older kernels (reportedly also 5.4), but this is untested.
There is some manual work required to get suspend and the fingerprint sensor to work, so I left a comment, in the hopes that it may be found. It's probably infeasible to put a warning, since the firmware version and UEFI settings are hard to detect from nix.