doc: add writable and readable options to Duplex docs

Fixes: https://github.com/nodejs/node/issues/34382

PR-URL: https://github.com/nodejs/node/pull/34383


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Robert Nagy <ronagy@icloud.com>
Reviewed-By: Ricky Zhou <0x19951125@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>