TODO

Update Tetris screenshots
Support gtk4 Ruby gem now that it is fully supported in release 4.0.0
Support simpler syntax for wiring menu-bar menus and menu items
Do not set a default height for window (only default width)
Support simpler usage of box pack_start and pack_end
Consider automatically destroying dialogs on response event
Support drawing images with Web URLs
Set fill rule, line cap with ruby symbols
Take cairo sample screenshots in Linux
Take cairo sample screenshots in Windows
Improve spacing and consider using fonts in Tetris score lane