repl: add welcome message
PR-URL: https://github.com/nodejs/node/pull/25947 Reviewed-By: Jeremiah Senkpiel fishrock123@rocketmail.com Reviewed-By: Ruben Bridgewater ruben@bridgewater.de Reviewed-By: James M Snell jasnell@gmail.com Reviewed-By: Joyee Cheung joyeec9h3@gmail.com Reviewed-By: Sakthipriyan Vairamani thechargingvolcano@gmail.com