Function new_markdown_to_html_string 

pub fn new_markdown_to_html_string<'r>(
    parser_options: Options,
    renderer_options: Options,
    parser_extension: impl ParserExtension,
    renderer_extension: impl RendererExtension<'r, String>,
) -> impl Fn(&mut String, &str) -> Result<()> + 'r

Creates a function that converts Markdown to HTML using the specified parser and renderer, with output written to a String.