Added flake development environment

flake.lock

@@ -0,0 +1,42 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1705331948,
+        "narHash": "sha256-qjQXfvrAT1/RKDFAMdl8Hw3m4tLVvMCc8fMqzJv0pP4=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "b8dd8be3c790215716e7c12b247f45ca525867e2",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-23.11",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs-unstable": {
+      "locked": {
+        "lastModified": 1705316053,
+        "narHash": "sha256-J2Ey5mPFT8gdfL2XC0JTZvKaBw/b2pnyudEXFvl+dQM=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "c3e128f3c0ecc1fb04aef9f72b3dcc2f6cecf370",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-unstable": "nixpkgs-unstable"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,29 @@
+{
+  description = "Development environment";
+
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-23.11";
+    nixpkgs-unstable.url = "nixpkgs/nixos-unstable";
+  };
+
+  outputs = { self, nixpkgs, nixpkgs-unstable }@inputs:
+  let
+      system = "x86_64-linux";
+      pkgs = nixpkgs.legacyPackages.${system};
+      overlay-unstable = final: prev: {
+        unstable = nixpkgs-unstable.legacyPackages.${prev.system};
+      };
+    in {
+      devShells.x86_64-linux.default =
+        pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [
+            fish
+            python311Packages.mkdocs-material
+          ];
+
+          shellHook = ''
+            exec fish
+          '';
+        };
+  };
+}