Updated Working on GNU Linux (markdown)

Working-on-GNU-Linux.md

@@ -22,6 +22,9 @@ You need to install some required libraries; **ALSA** for audio, **Mesa** for Op
 ##### Fedora
     sudo dnf install alsa-lib-devel mesa-libGL-devel libX11-devel libXrandr-devel libXi-devel libXcursor-devel libXinerama-devel libatomic
 
+##### Arch Linux
+    sudo pacman -S alsa-lib mesa libx11 libxrandr libxi libxcursor
+
 #### Wayland
 
  > WARNING: Wayland building requires manual generation of some wayland specific files. GLFW support for Wayland is "experimental and incomplete". For more info check issue [#2666](https://github.com/raysan5/raylib/issues/2666)