feat: support wayland

.github/README.md

@@ -5,9 +5,8 @@
 </div>
 <br/>
 
-`media-controller` provides a GTK-3 always-on-top window with transparency
-support that displays the current volume/brightness right after changing it
-accordingly.
+`media-controller` provides a GTK always-on-top window with transparency support
+that displays the current volume/brightness right after changing it accordingly.
 
 It makes use of UNIX sockets so that if another instance is created while the
 first one is running, it doesn't create another window and simply updates the
@@ -18,6 +17,12 @@ content of the existing one providing a smooth experience.
 [Options used in the demo:
 `--color=#000000aa --font-description="BigBlueTerm437 Nerd Font Mono"`]
 
+In order to build the binary or the library you must pick a Cargo feature:
+
+- `regular`: For X11 and other systems, uses GTK3
+- `wayland`: For Wayland systems, uses GTK4 and GTK4 Layer Shell (make sure to
+  have [`gtk-layer-shell`](https://github.com/wmww/gtk-layer-shell) installed)
+
 ```
 media-controller v0.2.1
 Nuno David <email@ndavd.com>
@@ -39,11 +44,11 @@ Format --{option}={value}
     empty               Empty character used in the progress bar. Default: " "
 ```
 
-In order to make it work in your system simply create a new cargo project. Add
-the library:
+In order to make it work in your specific system, simply create a new cargo
+project and add the library with the respective feature enabled:
 
 ```
-cargo add media-controller
+cargo add media-controller --features wayland
 ```
 
 Then all it takes is implementing some functions. Your `main.rs` should look