doc: mark Node.js 10 as End-of-Life

PR-URL: https://github.com/nodejs/node/pull/38482


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Beth Griggs <bgriggs@redhat.com>
Reviewed-By: Nitzan Uziely <linkgoron@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Filip Skokan <panva.ip@gmail.com>