Snapshot-timemachine provides a polished interface to step through the
snapshots of a file made by a third-party snapshot or backup facility,
e.g. Btrfs, ZFS, etc.

Out of the box, it can detect snapshots made by Snapper, but it provides
a simple interface to add support for other snapshot facilities.

It provides two views: the timemachine (`snapper-timemachine') and the
timeline (`snapper-timeline').