set up a default config

shell.nix

@@ -0,0 +1,19 @@
+# Shell for bootstrapping flake-enabled nix and other tooling
+{ pkgs ? let
+    lock = (builtins.fromJSON (builtins.readFile ./flake.lock)).nodes.nixpkgs.locked;
+    nixpkgs = fetchTarball {
+      url = "https://github.com/nixos/nixpkgs/archive/${lock.rev}.tar.gz";
+      sha256 = lock.narHash;
+    };
+  in
+  import nixpkgs { overlays = [ ]; }
+, ...
+}: {
+  default = pkgs.mkShell {
+    NIX_CONFIG = "extra-experimental-features = nix-command flakes repl-flake";
+    nativeBuildInputs = with pkgs; [
+      home-manager
+      git
+    ];
+  };
+}