We’ve released new documentation about backing up, restoring and migrating Hook data:
Those two Help pages do not refer to the current export and import functions because they will be removed from the user interface in Hook’s transition out of beta to golden master. We intend to reintroduce them in a different form later.
Regarding the second document: Hook does not yet provide a mechanism for syncing between Macs. However, there are ways to use Hook on multiple machines for technology enthusiasts, which are discussed there.