docs: clarify CommonJS and ES module examples in Node.js introduction

[sumitjhacodes]

Summary

This PR adds a brief explanation of the two server examples in the "Introduction to Node.js" page.

Changes

• Clarify that both examples create the same HTTP server.
• Explain that the first example uses the CommonJS module system (require()), while the second uses ECMAScript modules (import).
• Mention that the choice depends on the project's module system and configuration.

Motivation

While reading the introduction as a beginner, I noticed that the documentation presents both CommonJS and ES module examples without explaining why there are two versions. This small addition provides context for new users and helps them understand the purpose of each example without changing the existing content.

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Project	Deployment	Actions	Updated (UTC)
nodejs-learn	Ready	Preview	Aug 2, 2026 3:04pm

[cursor]

PR Summary

Low Risk
Documentation-only wording in a getting-started guide; no runtime or build behavior changes.

Overview
Adds a short paragraph after the dual Hello World server snippets on Introduction to Node.js, so readers know why both blocks appear.

The new text states that the CommonJS (require()) and ESM (import) samples build the same server, links to the Node.js module docs, and notes that the choice follows the project’s module setup. No code or run instructions are changed.

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[github-actions]

👋 Codeowner Review Request

The following codeowners have been identified for the changed files:

Team reviewers: @nodejs/nodejs-website

Please review the changes when you have a chance. Thank you! 🙏

[avivkeller]

Can you include links?

[sumitjhacodes]

Thanks for the suggestion! I'll update the paragraph to include links to the CommonJS and ECMAScript modules documentation.