doc: add links for repl.ReplServer

Add links to the class definition for repl.ReplServer in places where it
would be helpful.

PR-URL: https://github.com/nodejs/node/pull/23005


Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>