Function doc_line_text 

pub fn doc_line_text(source: &str, span: Span) -> &str

The text of a TokenKind::DocLine token: everything after the marker, less one separating space or tab, less a closer (#2203: a final run of exactly the opener’s dashes, preceded by whitespace, with that whitespace), and less the line ending. Further indentation is kept, so a doc line can indent a Markdown code block. A legacy --| line (#1888) has no closer.