Add source map to the output HTML of markdown-it.
yarn add markdown-it-source-map
import markdownIt from 'markdown-it'
import markdownItSourceMap from 'markdown-it-source-map'
const mdi = markdownIt()
mdi.use(markdownItSourceMap)
mdi.render('# hello world') // <h1 data-source-line="1">hello world</h1>
yarn build
yarn test