This commit adds Maciej Sypień's port [1] of Pavel Pertsev's gruvbox
color scheme [2] for vim.

[1] https://github.com/egel/terminator-gruvbox
[2] https://github.com/morhetz/gruvbox

Motivation for this change

To be able to use this color scheme via nixpkgs.

Things done

This is my first PR into this repo. I tested that this addition works on my machine by running against my fork of nixpkgs. I am more than happy to do any additional testing needed.

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• [X ] Fits CONTRIBUTING.md.

Notify maintainers

cc @