Add Node.js example

[kateinoigakukun]

No description provided.

[Copilot]

Pull request overview

This PR adds a Node.js example demonstrating JavaScriptKit usage in Node.js environments and introduces comprehensive documentation about the package output structure generated by the swift package js command. The changes make the platform setup functions more flexible by making their parameters optional with sensible defaults.

Key changes:

• New documentation article explaining the structure and usage of generated JavaScript packages
• Node.js example showing how to instantiate and run Swift code in Node.js
• Optional parameters for defaultNodeSetup() and defaultBrowserSetup() functions to simplify common use cases

Reviewed changes

Copilot reviewed 9 out of 11 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
Sources/JavaScriptKit/Documentation.docc/Documentation.md	Adds link to new Package Output Structure article
Sources/JavaScriptKit/Documentation.docc/Articles/Package-Output-Structure.md	New comprehensive documentation covering package structure, core files, and usage examples for browser and Node.js
Plugins/PackageToJS/Templates/platforms/node.js	Makes options parameter optional with default value and provides fallback for spawnWorker
Plugins/PackageToJS/Templates/platforms/node.d.ts	Updates type definitions to reflect optional parameters
Plugins/PackageToJS/Templates/platforms/browser.js	Adds optional chaining for options parameter access (has implementation issues)
Plugins/PackageToJS/Templates/platforms/browser.d.ts	Makes options and spawnWorker parameters optional
Examples/NodeJS/main.mjs	Node.js example demonstrating Swift/JS interop
Examples/NodeJS/Sources/NodeJS/NodeJS.swift	Swift code that exports a greeting function to JavaScript
Examples/NodeJS/README.md	Instructions for running the Node.js example
Examples/NodeJS/Package.swift	Swift package manifest for Node.js example
Examples/NodeJS/.gitignore	Standard Swift project gitignore file

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[Copilot]

When HAS_IMPORTS is defined, the getImports function is called unconditionally, but options may be undefined. This will cause a runtime error: Cannot read properties of undefined (reading 'getImports').

Consider using optional chaining with a fallback: return options?.getImports?.() ?? {}

Suggested change

	getImports() { return options?.getImports() },
	getImports() { return options?.getImports?.() ?? {} },

[Copilot]

The module property is required by InstantiateOptions but can be undefined when options is not provided. This could lead to runtime errors during instantiation.

Consider either requiring module in the options parameter or providing a sensible default/error handling.