Back up individual registry keys from Wine prefixes instead of whole *.reg file

[mtkennerly]

What's your idea?

Right now, for games that are known to use registry saves, Ludusavi backs up the full system.reg, user.reg and userdef.reg files from Wine prefixes. It would be nice to back up individual keys/values, similar to how Ludusavi generates a registry.yaml file on Windows.

I've created a crate that can be used for this: Regashii, although it doesn't currently preserve some of the special formatting that Wine reg files use (namely numbers after keys like [Software\\Wine\\Printing\\Spooler] 1128518253, and special options like #arch=win64). I'll try to set up a Wine prefix for testing first.