add in some connection for notifications of updates from within Documents

[heckj]

basic syncing is working with everything here, but it's not yet coordinated between the network providers

• add something that watches the Documents for updates (it's already ObservableObject, so that can likely be used as a trigger) in ordering to coordinate updates across the network
• sort this out with the concept of having a weak var today that can drop the connections - having something watching inside repo would make this a stronger connection in order to get the relevant updates, so we might need to be explicit abound handling memory scenarios where we'd otherwise normally purge.

[heckj]

resolved with #57