Function for

packages/dev/docs/src/Layout.js:462–466

(let category of [...pageCategories].sort())

      categories.push(category);
    } else if (category === '...') {
      for (let category of [...pageCategories].sort()) {
        if (!CATEGORY_ORDER.includes(category)) {
          categories.push(category);
        }
      }
    }
  }