Simplify something

extras/overlays.nix

@@ -0,0 +1,19 @@
+# This file defines overlays
+{inputs, ...}: {
+  # This one brings our custom packages from the 'pkgs' directory
+  additions = final: _prev: import ./pkgs {pkgs = final;};
+
+  # This one contains whatever you want to overlay
+  selfsuper = (self: super: {
+    mpv = super.mpv.override {
+      scripts = with self.mpvScripts; [mpris sponsorblock thumbnail];
+    };
+  });
+  
+  finalprev = (final: prev: {
+    unstable = import inputs.nixpkgs-unstable {
+      system = final.system;
+      config.allowUnfree = true;
+    };
+  });
+}