@x-govuk/govuk-eleventy-plugin/src/markdown-it/table-of-contents.js

Write documentation using Markdown and publish it using GOV.UK styles

/**
 * Render a table of contents
 *
 * @param {Function} md - markdown-it instance
 */
export function tableOfContentsRules(md) {
  const { rules } = md.renderer

  rules.toc_open =
    () => `<nav class="app-contents-list" aria-label="Contents" role="navigation">
    <h2 class="app-contents-list__title">Contents</h2>\n`

  rules.toc_close = () => '</nav>'
}