Update link.md (#20435)
Update link.md (#20435)

Added the `locale` prop in the Link documentation. At the moment it is only stated in the i18n doc.
azukaru/next.js,JeromeFitz/next.js,zeit/next.js,azukaru/next.js,azukaru/next.js,flybayer/next.js,zeit/next.js,JeromeFitz/next.js,azukaru/next.js,zeit/next.js,JeromeFitz/next.js,flybayer/next.js,flybayer/next.js,JeromeFitz/next.js,flybayer/next.js