Function complete_markdown_facts 

fn complete_markdown_facts<'a>(
    root: &Path,
    nodes: &[Node],
    graphs: &[impl Borrow<SymbolGraph>],
    symbols: &'a SymbolBuildStage,
    control: &IndexWorkControl,
) -> Result<BTreeMap<String, Cow<'a, MarkdownFacts>>, CliError>

Overlay staged Markdown facts and parse only persisted graphs not parsed in this operation.