Add support for yuzu and ryujinx.

nix/steam_deck/configuration/roles/ryujinx/default.nix

@@ -0,0 +1,39 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  imports = [ ];
+
+  options.me = {
+    ryujinx.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = "Whether we want to install ryujinx.";
+    };
+  };
+
+  config = lib.mkIf config.me.ryujinx.enable (
+    lib.mkMerge [
+      (lib.mkIf config.me.graphical {
+        # This needs to be read-write so we use me.copy.file to copy the file.
+        me.copy.file.".config/Ryujinx/Config.json" = {
+          source = ./files/Config.json;
+          mode = "0644";
+        };
+
+        me.persist.directories = [
+          ".config/Ryujinx/bis"
+          ".config/Ryujinx/games"
+          ".config/Ryujinx/sdcard"
+          ".config/Ryujinx/system"
+        ];
+        me.state.directories = [ ];
+      })
+    ]
+  );
+}