[Suggestion] Automatic Backups

[SolarLune]

Related to #2508, it seems like it might be a good idea to create automatic backups, perhaps on a timer, up to a certain maximum number of backups. After the maximum number of backups is reached, TIC-80 would delete the oldest backup and create a new one. The numbers for maximum number of backups and the timer could be user-configurable, with some sensible defaults (maybe every 10 minutes and 3 backups to start, for example).