Recommendation: Only exclude Docker overlay2 from snapshots

[andrewvaughan]

The /var/lib/docker folder contains some things people may want to back up, such as the volumes directory, especially, if their configurations use named volumes.

Generally, the only true "large" directory in the folder that is rebuildable is the overlay2 directory (as far as I'm aware) which contains all of your image layers. I'm not an expert on how Docker works in its folder directory, so don't take this as expert advice, but it seems like only excluding the docker/overlay2 folder would be a better choice for snapshot exclusion than the entire docker configuration.