Create a generalized "Backup Guide"

[nicknamenamenick]

Something to cover to backup personal files in the Home directory, explain where Flatpak userdata lives, and a couple of recommended backup tool.

Put it under the "General tab".

[jkirk]

I am just about to reinstall Bazzite and a "Backup Guide" would have come handy.

As I have to do it by my own, I'd like to help with the documentation. Before doing it "my way" are there any tools you prefer which make the life easier for an ordinary Bazzite user? (The draft mentions "Pika backup" and "Deja dup". I haven't used them? Are they still recommended and available out of the box in Bazzite?)

Some background: I am long time Debian user and have no experience with Bazzite and I made a "mistake" and replaced my Gaming/Windows system with Bazzite.
Unfortunately there are some games which do not work with Linux / Bazzite so I decided to go for a dual-boot setup.
The Dual Boot Preliminary and Post-Installation Setup Guide states that the "same drive method" must be done before installing Bazzite (is it possible to shrink the Bazzite/btrfs partition and install Windows afterwards? If yes, a "Dual-Boot Windows after Bazzite was installed"-Guide would be awesome too).
So I'd like to take a full backup of my Bazzite data, install Windows on a separate partition, reinstall Bazzite with Dual-Boot and restore the backup.