Document all events

[aral]

The following events are currently not documented.

I’m suggesting preliminary descriptions/posing questions based on event names; please contribute and revise as necessary:

• content: content has loaded. (What is the use case of the event handler? e.g., “You can start mirroring with mirror-folder")
• syncing: content is syncing. (What is the use case of the event handler? Can we get progress stats, etc? Sample code demonstrating use?)
• sync: sync is complete. (How is this different from the content event? Sample code demonstrating use?)
• appending: content is being appended to. (How is this different from the syncing event? Sample code demonstrating use?)
• append: append complete? (What is the use case of the event handler? Sample code demonstrating use?)

Also for the ready and error events, it would be helpful to have suggestions of how to best respond to these events, if we have such suggestions. (e.g., as per https://github.com/mafintosh/mirror-folder/issues/16, something along the lines of “The ready event does not signal that the content is ready, only that the archive is ready to <what is it ready to do, exactly?>. Here you can… ."