Nixos shenanigans; refactor script

[famfo]

• adds a check if the full path to proton is given, for example when using nixpkgs proton-ge-bin with nix path-info --impure --expr '(import <nixpkgs> {})' proton-ge-bin.steamcompattool
• refactors some of the bash
• bumps the version

[ninelore]

thanks