docs: enhance README with additional details

[chenjiahan]

This pull request updates the README.md to provide more comprehensive project information and documentation links.

[Copilot]

Pull request overview

This pull request enhances the README.md by expanding the project description and adding three new documentation sections: Documentation (with API reference link), Credits (acknowledging webpack-sources contributors), and License information.

Key Changes:

• Enhanced project description to include details about composable sources and source map utilities
• Added Documentation section with API reference link
• Added Credits and License sections

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[codspeed-hq]

CodSpeed Performance Report

Merging #209 will not alter performance

_{Comparing improve_readme_0102 (470a6e3) with main (ee9c518)¹}

Summary

✅ 11 untouched
⏩ 6 skipped²

Footnotes

1. No successful run was found on main (74beb79) during the generation of this report, so ee9c518 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

2. 6 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩