feat: add flake devshell

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1739736696,
+        "narHash": "sha256-zON2GNBkzsIyALlOCFiEBcIjI4w38GYOb+P+R4S8Jsw=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "d74a2335ac9c133d6bbec9fc98d91a77f1604c1f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,34 @@
+{
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs = {
+    nixpkgs,
+    self,
+  }: let
+    pkgs = nixpkgs;
+
+    mkAllSystems = genAttrs [
+      "aarch64-darwin"
+      "aarch64-linux"
+      "i686-linux"
+      "x86_64-darwin"
+      "x86_64-linux"
+    ];
+
+    inherit (lib) genAttrs;
+    inherit (pkgs) alejandra lib;
+  in {
+    formatter = mkAllSystems (system: alejandra);
+
+    devShells = mkAllSystems (system: let
+      pkgs = nixpkgs.legacyPackages.${system};
+
+      inherit (pkgs) mkShell;
+    in {
+      default = mkShell {
+        nativeBuildInputs = [pkgs.hugo];
+        shellHook = "hugo server";
+      };
+    });
+  };
+}