Add nix shell file

Author: 0xhenrique

.envrc

@@ -1 +1 @@
-use guix
+use nix

shell.nix

@@ -0,0 +1,17 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+  buildInputs = with pkgs; [
+    pkg-config
+    rustc
+    cargo
+    rust-analyzer
+    python3
+    ruby
+    gcc
+    go
+    nodejs
+    lua
+    bash
+  ];
+}