Add splash screen toggle (#2568)

Add preferences option to toggle splash screen

src/libslic3r/AppConfig.cpp

@@ -231,6 +231,12 @@ void AppConfig::set_defaults()
     if (get("stealth_mode").empty()) {
         set_bool("stealth_mode", false);
     }
+
+    // Orca
+    if(get("show_splash_screen").empty()) {
+        set_bool("show_splash_screen", true);
+    }
+
     if (get("show_model_mesh").empty()) {
         set_bool("show_model_mesh", false);
     }