Add Nix flakes to the docs (#155)

* Add Nix flakes to the docs

* revert changes to package.json

.envrc

@@ -0,0 +1,5 @@
+if ! has nix_direnv_version || ! nix_direnv_version 2.3.0; then
+    source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/2.3.0/direnvrc" "sha256-Dmd+j63L84wuzgyjITIfSxSD57Tx7v51DMxVZOsiUD8="
+fi
+use flake
+# vi: ft=sh

.gitignore

@@ -16,4 +16,5 @@ yarn-error.log
 out/*
 out
 .dccache
-*.code-workspace
+*.code-workspace
+.direnv

flake.nix

@@ -0,0 +1,29 @@
+{
+  description = "Webb docs development environment";
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        overlays = [ ];
+        pkgs = import nixpkgs {
+          inherit system overlays;
+        };
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          name = "docs";
+          nativeBuildInputs = [ ];
+          buildInputs = [
+            # Nodejs
+            pkgs.nodePackages.typescript-language-server
+            pkgs.nodejs_18
+            pkgs.nodePackages.yarn
+          ];
+          packages = [ ];
+        };
+      });
+}