Automatically create theme folders, and add an action to open them

Signed-off-by: TheKodeToad <TheKodeToad@proton.me>

launcher/ui/MainWindow.h

@@ -111,16 +111,18 @@ private slots:
 
     void on_actionChangeInstIcon_triggered();
 
-    void on_actionViewInstanceFolder_triggered();
-
     void on_actionViewLauncherRootFolder_triggered();
 
+    void on_actionViewInstanceFolder_triggered();
+    void on_actionViewCentralModsFolder_triggered();
+
+    void on_actionViewIconThemeFolder_triggered();
+    void on_actionViewWidgetThemeFolder_triggered();
+
     void on_actionViewSelectedInstFolder_triggered();
 
     void refreshInstances();
 
-    void on_actionViewCentralModsFolder_triggered();
-
     void checkForUpdates();
 
     void on_actionSettings_triggered();