Document modules that need Allow From Derivation

[vdbe]

An extra readme segment that specifies which modules require Allow From Derivation
or/and an option to exclude those modules from the global enable option.

[vdbe]

Willing to implement it myself, just let me know.

[getchoo]

documenting what modules contain it would be nice. feel free to PR it to our FAQ

regarding excluding them from the global enable option: i can see why this might be a requested feature, but i feel would overcomplicate how we actually implement catppuccin.enable for what's a pretty niche feature. giving a neat list of modules should be good enough for most i'd imagine

[vdbe]

For the option my idea was to have 1 place (2 nixos and home manager) where you use mkOverride with priority over MkOptionDefault.

This way you don't need to touch mkCatppuccinOpt and can possibly generate the description for documentation instead of a Readme/FAQ segment.

Don't know yet how you would test it so that it is not a best effort option.

Would this implementation be overcomplicated?