Function api_ref_headings

perro_website/src/docs.rs:452–454

(markdown: &str)

                let marker = format!("id=\"{}\"", heading.id);
                if !doc.html.contains(&marker) {
                    failures.push(format!(
                        "{} renders no id for heading `{}`",
                        doc.slug, heading.id
                    ));
                }
            }