doc: fix numbering in require algorithm

Refs: https://github.com/nodejs/node/pull/29327

PR-URL: https://github.com/nodejs/node/pull/30117


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>