[Nothing]: add nix develop support

Author: jinzhongjia

.envrc

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

.gitignore

@@ -1,2 +1,3 @@
 zig-cache
 zig-out
+.direnv

flake.lock

@@ -0,0 +1,57 @@
+{
+  description = "For lua environment";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    zig-overlay.url = "github:mitchellh/zig-overlay";
+    zls-overlay.url = "github:zigtools/zls";
+  };
+
+  outputs = { self, nixpkgs, ... }@ inputs:
+    let
+      systems = [
+        # "aarch64-linux"
+        # "i686-linux"
+        # "aarch64-darwin"
+        # "x86_64-darwin"
+        "x86_64-linux"
+      ];
+      # This is a function that generates an attribute by calling a function you
+      # pass to it, with each system as an argument
+      forAllSystems = nixpkgs.lib.genAttrs systems;
+    in
+    {
+      # This is for using nix direnv and flake develop environment
+      devShells = forAllSystems (system:
+        let
+          pkgs = import nixpkgs {
+            inherit system;
+            overlays = [
+              inputs.zig-overlay.overlays.default
+              (final: prev: {
+                zlspkgs = inputs.zls-overlay.packages.${system}.default;
+              })
+            ];
+          };
+        in
+        {
+          default =
+            pkgs.mkShell {
+              packages = with pkgs; [
+                zigpkgs.default
+                zls
+                nodePackages.live-server
+              ];
+            };
+
+          nightly =
+            pkgs.mkShell {
+              packages = with pkgs;[
+                zigpkgs.master
+                zlspkgs
+                nodePackages.live-server
+              ];
+            };
+        });
+    };
+}