获取所有frontmatter

[axolo]

// .vitepress/config.js

import fs from 'fs'
const buildPages = []

export default {
  async transformPageData(pageData) {
    buildPages.push(pageData)
  },
  async buildEnd(siteConfig) {
    fs.writeFileSync('pages.json', JSON.stringify(buildPages), { encoding: 'UTF-8' })
  }
}