doc: add esm examples to `node:readline`

[mfdebian]

This PR adds the missing ESM counterparts of the CJS examples for the Readline documentation.

I've tested every single example and they all work/behave as expected.

Best regards!

[mfdebian]

hello @RedYetiDev I've made the changes you requested, can I kindly ask you to review once more and if everything looks good to you you can approve the PR? :blush: if not, let me know what other changes you'd like me to make!

I generally try to not change everything too much just so there's a lot of consistency between the CJS and ESM examples for new users but let me know your thoughts!

Thanks in advance! :raised_hands:

[nodejs-github-bot]

Landed in a7c9f85f2f3dc7c66ee6b19429e9568722ebc1b6