Recording here what we discussed in Slack:

- 'Zettel' is the term we're using specifically for kind 30041 events.  They are intended to be bite-sized notes.
- 'Index' is the term we're using for kind 30040 events.
- 'Event' is the generic term.  Wiki entries, long-form articles, indices, and zettels are all 'events.'  If we don't have a specific term for an event kind in a given instance, we'll call it an 'event.'

Terms like 'node,' 'block,' and 'section' are specific to Asciidoctor.  I can add details in the code comments explaining how we are using different terms throughout the parser logic.