fix typo in `eslint-plugin-next` code comments (#15583)
fix typo in `eslint-plugin-next` code comments (#15583)

(p.s. excited to use this package. thank you.)
azukaru/next.js,flybayer/next.js,JeromeFitz/next.js,azukaru/next.js,JeromeFitz/next.js,zeit/next.js,flybayer/next.js,zeit/next.js,zeit/next.js,azukaru/next.js,JeromeFitz/next.js,flybayer/next.js,JeromeFitz/next.js,flybayer/next.js,azukaru/next.js