Added argc check

src/main.cpp

@@ -1,9 +1,22 @@
+#include <qmessagebox.h>
 #include <qapplication.h>
 #include "MainWindow.hpp"
 
 int main(int argc, char** argv)
 {
 	QApplication app(argc, argv);
+
+	if (argc < 2)
+	{
+		QMessageBox no_args_error_box;
+		no_args_error_box.setWindowTitle("Error");
+		no_args_error_box.setText("Too few arguments. Need at least one CSV file.");
+		no_args_error_box.setIcon(QMessageBox::Icon::Critical);
+		no_args_error_box.exec();
+
+		return 1;
+	}
+
 	MainWindow window;
 	window.show();