Add openrc support

[supasonix-zuv]

[supasonix-zuv]

whoops, accidentally commented before I was done. Anyway, it'd be cool if other OpenRC users could run this without having to write their own init file. I wrote up one, but I've never done it before, so IDK if it's any good. amdgpu-fan.txt I also wrote the config file, cause I think openrc wants it even if it doesn't have any settings, but IDK. amdgpu-fanconf.txt