doc: remove warning against readable/readable.read

Remove suggestion to avoid `readable` event and `readabe.read()` method.
No explanation was provided for this suggestion.

Backport-PR-URL: https://github.com/nodejs/node/pull/22380
PR-URL: https://github.com/nodejs/node/pull/19193


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Chen Gang <gangc.cxy@foxmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>