docs(package-json): add documentation for type field (#8793)

## Description

This PR adds documentation for the `type` field in package.json, which
controls whether Node.js treats .js files as ES modules or CommonJS
modules.

## Changes

- Added a new section documenting the `type` field
- Explained the two possible values: `module` and `commonjs`
- Provided examples for both module types
- Added a note about .mjs and .cjs file extensions
- Linked to Node.js official documentation

## Fixes

Closes #8376

## Context

The `type` field is a crucial part of package.json for modern Node.js
projects, especially with the widespread adoption of ES modules. As
reported in issue #8376, this field was not documented in npm's
package.json reference, which caused confusion for developers trying to
understand how to configure their packages for ESM or CommonJS.

This documentation clarifies:
1. How to enable ES modules in a package (`"type": "module"`)
2. How to explicitly use CommonJS (`"type": "commonjs"`)
3. The default behavior when `type` is omitted (CommonJS)
4. That file extensions (.mjs/.cjs) override the type field

## Type of Change

- [x] Documentation update

Co-authored-by: Max Black <[email protected]>

Author: MaxBlack-dev

docs/lib/content/configuring-npm/package-json.md

@@ -335,6 +335,12 @@ For most modules, it makes the most sense to have a main script and often not mu
 
 If `main` is not set, it defaults to `index.js` in the package's root folder.
 
+### type
+
+The `type` field defines how Node.js should interpret `.js` files in your package. This field is not used by npm.
+
+See the [Node.js documentation on the type field](https://nodejs.org/api/packages.html#type) for more information.
+
 ### browser
 
 If your module is meant to be used client-side the browser field should be used instead of the main field.