added nix flake so I can work on it

Author: nemonical

crates.nix

@@ -0,0 +1,16 @@
+{...}: {
+  perSystem = {
+    pkgs,
+    config,
+    ...
+  }: let
+    # TODO: change this to your crate's name
+    crateName = "freenet-scaffold";
+  in {
+    # declare projects
+    # TODO: change this to your crate's path
+    nci.projects.${crateName}.path = ./.;
+    # configure crates
+    nci.crates.${crateName} = {};
+  };
+}

flake.nix

@@ -0,0 +1,34 @@
+{
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  inputs.nci.url = "github:yusdacra/nix-cargo-integration";
+  inputs.nci.inputs.nixpkgs.follows = "nixpkgs";
+  inputs.parts.url = "github:hercules-ci/flake-parts";
+  inputs.parts.inputs.nixpkgs-lib.follows = "nixpkgs";
+
+  outputs = inputs @ {
+    parts,
+    nci,
+    ...
+  }:
+    parts.lib.mkFlake {inherit inputs;} {
+      systems = ["x86_64-linux"];
+      imports = [
+        nci.flakeModule
+        ./crates.nix
+      ];
+      perSystem = {
+        pkgs,
+        config,
+        ...
+      }: let
+        # shorthand for accessing this crate's outputs
+        # you can access crate outputs under `config.nci.outputs.<crate name>` (see documentation)
+        crateOutputs = config.nci.outputs."freenet-scaffold";
+      in {
+        # export the crate devshell as the default devshell
+        devShells.default = crateOutputs.devShell;
+        # export the release package of the crate as default package
+        packages.default = crateOutputs.packages.release;
+      };
+    };
+}