base mpv config as mkdefault so it can be overriden

home-manager/base.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ pkgs, lib, ... }:
 
 {
   imports = [
@@ -37,7 +37,7 @@
       package = pkgs.brave;
     };
 
-    mpv = {
+    mpv = lib.mkDefault {
       enable = true;
       config = {
         screenshot-directory = "~/Pictures/";