Add nix flake

Author: azuwis

.envrc

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

.gitignore

@@ -10,7 +10,6 @@ node_modules
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
-yarn.lock
 
 # Editor directories and files
 .idea

flake.lock

@@ -0,0 +1,34 @@
+{
+  inputs.nixpkgs.url = "nixpkgs";
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+  inputs.devshell.url = "github:numtide/devshell";
+  inputs.devshell.inputs.nixpkgs.follows = "nixpkgs";
+  inputs.devshell.inputs.flake-utils.follows = "flake-utils";
+
+  outputs = { self, nixpkgs, flake-utils, devshell }:
+    flake-utils.lib.eachDefaultSystem (system: let
+      pkgs = import nixpkgs {
+        inherit system;
+        overlays = [ devshell.overlay ];
+      };
+      nodeModules = pkgs.mkYarnModules rec {
+        pname = "zigbee2mqtt-networkmap-node-modules";
+        version = "1.0";
+        packageJSON = ./package.json;
+        yarnLock = ./yarn.lock;
+      };
+    in {
+      devShell = pkgs.devshell.mkShell {
+        env = [{
+          name = "NODE_OPTIONS";
+          value = "--openssl-legacy-provider";
+        }];
+        devshell.startup.yarn.text = ''
+          ln -sf ${nodeModules}/node_modules .
+        '';
+        packages = with pkgs; [
+          yarn
+        ];
+      };
+    });
+}