Upgrade with-mdx example from mdx 0.16 → 1.1 (#8142)
Upgrade with-mdx example from mdx 0.16 → 1.1 (#8142)


flybayer/next.js,JeromeFitz/next.js,BlancheXu/test,zeit/next.js,flybayer/next.js,JeromeFitz/next.js,flybayer/next.js,JeromeFitz/next.js,flybayer/next.js,azukaru/next.js,azukaru/next.js,azukaru/next.js,BlancheXu/test,JeromeFitz/next.js,BlancheXu/test,zeit/next.js,zeit/next.js,azukaru/next.js