Add support for small screens (main window height)

[BigBoiCJ]

See https://cs.rin.ru/forum/viewtopic.php?p=3058172#p3058172 and https://cs.rin.ru/forum/viewtopic.php?p=3058335#p3058335

The main window could be a big too tall for smaller screens when the console appears. Might be good to add a screen size detection and add scroll support for the main window. The actual size of the main window could depend on the detected screen height.