Add flake for managing nodeJS version

Author: mjrussell

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -9,3 +9,5 @@
 /.psa*
 /.vscode/
 /.spago/
+.direnv
+*.swp

flake.lock

@@ -0,0 +1,34 @@
+{
+  description = "Provide an environment for working in this repo";
+
+  # to handle mac and linux
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  # we want to use a consistent nixpkgs across developers.
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+
+  outputs = all@{ self, nixpkgs, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+        };
+        packages =
+          let
+            # everything we want available in our development environment that isn't managed by
+            # npm, spago
+            # we do not differentiate between libraries needed for building and tools at the moment.
+            sharedPackages = with pkgs; [
+              nodejs-16_x
+            ];
+          in
+            sharedPackages;
+      in {
+        # produce our actual shell
+        devShell = pkgs.mkShell rec {
+          # make our packages available
+          buildInputs = packages;
+        };
+      }
+    );
+}