Open .mid file passed as argument

[fpesari]

Hello,

midieditor lacks a very convenient feature: open a .mid file passed as the first argument, like this:

midieditor FILENAME

this means that you cannot even open a .mid file with midiedtiro in a file manager by double-clicking on it.

[eoan-ermine]

It's already done

midieditor/src/main.cpp

Lines 84 to 90 in 1b42f00

	MainWindow* w;
	if (argc == 2)
	w = new MainWindow(argv[1]);
	else
	w = new MainWindow();
	w->showMaximized();
	return a.exec();