add tests to make sure that the content of the doc/node.1 file
is kept in snyc with the content of the doc/api/cli.md file
(to make sure that when a flag or environment variable is added
or removed to one, the same change is also applied to the other)
PR-URL: https://github.com/nodejs/node/pull/58878
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
Reviewed-By: James M Snell <jasnell@gmail.com>