doc: fix description of named exports detection

[csr632]

The tool used to do named exports detection should be cjs-module-lexer, not esm-module-lexer.
Reference: https://github.com/nodejs/node/blob/5e57d24d325f0aea74394f78ebdc06857cca77b1/doc/api/esm.md

[nodejs-github-bot]

Review requested:

• @nodejs/modules

[richardlau]

This overlaps with #44262.

[JakobJingleheimer]

Thanks for the contribution! As Richard mentioned, there is already an approved PR fixing this.

P.S. The links at the bottom of the doc file must be in alphabetical order. The current error is misleading:

Unordered reference ("cjs-module-lexer" should be before "the full specifier path")

The new link you added must indeed be listed above the one immediately above it, but it actually must be far above.

[csr632]

Thanks for the review! I am closing this PR.