Function render_markdown 

pub fn render_markdown<I, W>(events: I, w: &mut W) -> Result<()>
where
    I: IntoIterator<Item = Result<TranscriptEvent>>,
    W: Write,

Streams events as Markdown to w.

Groups consecutive Final events by speaker into one paragraph each (a paragraph being one timestamped line followed by a blank line), flushing at every speaker-paragraph boundary so the reader sees transcript output as it commits. Partial and Endpoint events are dropped.