Don't force users to load rom from terminal or by dragging and dropping onto executable file. Instead, open a blank window and use SDL's drag&drop feature

include/emulator.hpp

@@ -47,7 +47,7 @@ class Emulator {
 	static constexpr u32 width = 400;
 	static constexpr u32 height = 240 * 2;  // * 2 because 2 screens
 	ROMType romType = ROMType::None;
-	bool running = true;
+	bool running = true, romLoaded = false;
 
 #ifdef PANDA3DS_ENABLE_HTTP_SERVER
 	HttpServer httpServer;