doc: add require statement in the example

PR-URL: https://github.com/nodejs/node/pull/35554


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Harshitha K P <harshitha014@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>