doc: clarify using crlfDelay with fs streams

PR-URL: https://github.com/nodejs/node/pull/16259
Fixes: https://github.com/nodejs/node/issues/16077


Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>