Add nix development shell with a flake (#590)

* Add nix development shell with a flake

* Update contrib/README.md

---------

Co-authored-by: josie <[email protected]>

Author: nyonson

contrib/README.md

@@ -0,0 +1,3 @@
+# Community Contributions
+
+Contains community-contributed resources for Warnet. These contributions are not officially supported or maintained.

contrib/nix/flake.lock

@@ -0,0 +1,42 @@
+{
+  description = "Warnet python development environment";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [
+            python3
+            python3Packages.pip
+            # K8 dependencies for local cluster deployment.
+            minikube
+            kubectl
+            kubernetes-helm
+          ];
+
+          # Install project dependencies and executable.
+          shellHook = ''
+            # Create a virtual environment if it doesn't exist.
+            if [ ! -d ".venv" ]; then
+              python -m venv .venv
+            fi
+            
+            # Activate the virtual environment.
+            source .venv/bin/activate
+            # Install the project in editable mode.
+            pip install -e .
+
+            echo "WARNET DEVELOPMENT SHELL ENABLED"
+          '';
+        };
+      }
+    );
+}