rsnext/examples/with-markdown/next.config.js

const images = require('remark-images')
const emoji = require('remark-emoji')

const withMDX = require('@zeit/next-mdx')({
  options: {
    mdPlugins: [images, emoji]
  }
})

module.exports = withMDX({
  pageExtensions: ['js', 'jsx', 'mdx']
})