Please add a setting to import and export your Lutris library into a compressed zip or 7z file which can be imported again. This compressed file will contain all of your used runners and games and its data such as the banner image, game info, game options, runner options, all of it.
This way Lutris will have an official import/export feature to allow for gamers to export their library and back it up now and then and then be able to import it to their new gaming computers with just a few clicks.