ReadonlydepthIndentation depth in the rendered tree, from 0.
Optional ReadonlyiconReadonlylabelRow label: heading text, or a description of the block.
ReadonlylevelHeading level when type is a heading, otherwise 0.
ReadonlypathReadonlytypeNode type name (heading, codeBlock, table, …).
One row in the outline: a heading, or a notable non-heading block.