feat: dev setup

dev.nix

@@ -0,0 +1,27 @@
+# run with nix dev.nix
+# has everything installed for dev
+
+{ pkgs ? import <nixpkgs> {} }:
+with pkgs;
+let
+imports =
+    let agenixCommit = "42d371d861a227149dc9a7e03350c9ab8b8ddd68";
+    in
+    {
+      agenix = import
+        (builtins.fetchTarball {
+          url = "https://github.com/ryantm/agenix/archive/${agenixCommit}.tar.gz";
+          sha256 = "14sszf5s85i4jd3lc8c167fbxvpj13da45wl1j7wpd20n0fic5c1";
+        })
+        { inherit pkgs; };
+    };
+in mkShell {
+    # nativeBuildInputs is usually what you want -- tools you need to run
+    nativeBuildInputs = [
+        pkgs.buildPackages.git
+        pkgs.buildPackages.colmena
+        pkgs.buildPackages.nmap
+    ];
+
+    buildInputs = [ imports.agenix.agenix ];
+}