doc: document that stream.on('close') was changed in Node 10

See: https://github.com/nodejs/node/issues/25373
See: https://github.com/nodejs/node/pull/18438

PR-URL: https://github.com/nodejs/node/pull/25413


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>