Keep settings when updating TIC-80

[Skeptim]

I don't know if that's possible but it would be great to keep menu settings and config file settings when updating to a more recent TIC-80 version.

Currently, it's difficult to use themes and I have to change the gamepad settings each time I update TIC-80 because I use a special (bépo) keyboard.

[Skeptim]

Currently bookmarks are hardly usable because they do not persist across restart #1979 . When we make them persist across restart the best would be to do it in a way that they persist across update too.
I mention it so that this can be anticipated.