rsync section in moving-data tutorial

[JustBerkhout]

I think the moving-data tutorial would benefit from a section on rsync. I think the benefits of incremental copying, and synchronization (i.e. destination deletes) make it worthwhile introducing entry-level users to this data-moving-option in the Nectar context.

Similarity to scp (already in the tutorial) could be emphasised.
The automatability on rsync is strong
recovering from interrupted transfers is a good feature.