doc: add note explaining ESM vs CommonJS startup performance difference

[pudinaman]

No description provided.

[nodejs-github-bot]

Review requested:

• @nodejs/loaders

[pudinaman]

This PR adds documentation explaining the observed performance difference
when importing the 'http' module using ESM (import) vs CommonJS (require).

• ESM imports eagerly evaluate all properties, causing a slight delay (~8–10 ms)
  for small scripts or CLIs.
• CommonJS require is lazy, so it loads faster for one-off executions.
• Recommended usage:
  • Use ESM imports for long-running server apps.
  • Use require for CLI or scripts where startup time matters.

Closes / References:

• Issue ESM import of http is slower compared to CommonJS #59686
• Issue doc: highlight difference in module loading between ESM and CommonJS #59815

[jsumners-nr]

Duplicate of #59815