Added a Nix/NixOS setup guide for Raylib

Working-on-GNU-Linux.md

@@ -204,6 +204,101 @@ cd raylib/src/
 make PLATFORM=PLATFORM_DESKTOP GRAPHICS=GRAPHICS_API_OPENGL_11 -B
 ```
 
+### Nix/NixOS
+1. Begin by downloading the latest stable release of raylib into your project folder. Use the following commands:
+```sh
+cd your-project-folder
+mkdir external
+wget https://github.com/raysan5/raylib/archive/refs/tags/5.5.tar.gz -P external/
+tar xvf external/5.5.tar.gz -C external/
+```
+
+2. Create a `flake.nix` file in the root folder of your project with the following content:
+```nix
+{
+  description = "Raylib development environment";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  };
+
+  outputs = { self , nixpkgs ,... }: let
+    system = "x86_64-linux";
+  in {
+    devShells."${system}".default = let
+      pkgs = import nixpkgs {
+        inherit system;
+      };
+    in pkgs.mkShell {
+      packages = [
+        pkgs.libGL
+
+        # X11 dependencies
+        pkgs.xorg.libX11
+        pkgs.xorg.libX11.dev
+        pkgs.xorg.libXcursor
+        pkgs.xorg.libXi
+        pkgs.xorg.libXinerama
+        pkgs.xorg.libXrandr
+
+        # Uncomment the line below if you want to build Raylib with web support
+        # pkgs.emscripten
+      ];
+    };
+  };
+}
+```
+
+3. Create the development environment with the dependencies using:
+```sh
+nix develop
+```
+
+</details>
+<details><summary> Or with nix channels </summary>
+
+Alternatively, you can create a `shell.nix` file in the root folder of your project with the following content:
+```nix
+{ pkgs ? import <nixpkgs> {} }:
+
+  pkgs.mkShell {
+    nativeBuildInputs = [
+      pkgs.libGL
+
+      # X11 dependencies
+      pkgs.xorg.libX11
+      pkgs.xorg.libX11.dev
+      pkgs.xorg.libXcursor
+      pkgs.xorg.libXi
+      pkgs.xorg.libXinerama
+      pkgs.xorg.libXrandr
+
+      # Web support (uncomment to enable)
+      # pkgs.emscripten
+    ];
+}
+```
+
+Then, run the following command to enter the nix-shell:
+```sh
+nix-shell
+```
+</details>
+
+4. To build raylib, navigate to the src directory inside the external/raylib-5.5 folder and run make:
+```sh
+cd external/raylib-5.5/src/
+make PLATFORM=PLATFORM_DESKTOP
+```
+
+5. Now you can compile your project with Raylib. The simplest possible Makefile for this would be:
+```makefile
+RAYLIB ?= ./external/raylib-5.5/src/
+
+all:
+    gcc src/main.c -I $(RAYLIB) -L $(RAYLIB) -lraylib -lGL -lm -lpthread -ldl -lrt -lX11
+```
+
 ## The simplest possible build command
 After installing raylib from source or package manager, you can build a project with this command (modify as necessary):
 ```