/// Splits multiline comments into lines and prefixes them with `#`.
pubfnformat_comment(txt:&str)-> String{
txt.lines().map(|txt|txt.trim()).filter(|txt|!txt.is_empty()).map(|txt|{if txt.starts_with('#'){
txt.to_owned()}else{format!("# {txt}")}}).collect::<Vec<_>>().join("\n")}