Feature request: Add support for flatpak apps

[hovancik]

Hi there,

I am using this library for Linux with ElectronJS app and users report, that it does not work with Flatpak distribution: hovancik/stretchly#1517 (comment)

Thanks!

[jwillikers]

It should be possible through the background portal, not that I'm familiar with it: https://github.com/flatpak/xdg-desktop-portal/blob/main/data/org.freedesktop.portal.Background.xml