adding nix support

[code4brot]

this commit adds nix support to intel_fw.

While the regular git pull -> cargo build -> cargo run approach is fine as is there might be ppl wanting to run this directly like nix run gh:platform-system-interface/intel_fw from their systems.

The flake uses naersk in order to evaluate the Cargo.toml and generate nix expressions from it. So there should be no need for any manual intervention after checking in flake.nix.
The flake makes use of flake-compat, so it's possible to invoke nix-build and nix-shell on it as well.

[orangecms]

That is a distro/packaging matter though?

I would like to kindly ask to keep those concerns to the distro or a fork.

Maybe create a tool that generates those files for this use case on demand, so it wouldn't need to be copied to every Rust project, if that makes sense?

Otherwise, I would end up having it all here - PKGBUILD, ebuild, specfile, Dockerfile, ...