Sync

Import these from @grafloria/engine.

On their own pages

• Classes: 6 classes.
• Functions: 5 functions.
• Interfaces: 21 interfaces.
• Types: 4 types.
• Awareness: The presence store for one peer: our own state, and everyone else's.
• CausalBuffer: Holds ops whose entity has not been added yet, and releases them the instant it is.
• SyncAdapter: Binds one Replica to one SyncTransport.
• UnreliableHub: A MemoryHub with the network's malice put back.