add nix devshell (flake based)

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1753489912,
+        "narHash": "sha256-uDCFHeXdRIgJpYmtcUxGEsZ+hYlLPBhR83fdU+vbC1s=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "13e8d35b7d6028b7198f8186bc0347c6abaa2701",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-25.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,27 @@
+# Template: https://nixos-and-flakes.thiscute.world/development/intro
+{
+  description = "Dev Shell for dobutterfliescry.net";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.05";
+  };
+
+  outputs = {nixpkgs, ...}: let
+    system = "x86_64-linux";
+  in {
+    devShells."${system}".default = let
+      pkgs = import nixpkgs {
+        inherit system;
+      };
+    in
+      pkgs.mkShell {
+        packages = with pkgs; [
+          bash
+          simple-http-server
+          imagemagick
+        ];
+
+        shell = "${pkgs.bash}/bin/bash";
+      };
+  };
+}