Add support for multiple documentation files

[kovart]

This PR introduces the ability to specify multiple documentation files, each with its own title, while maintaining backward compatibility. No modifications are required for existing projects.

Key Changes:

• Manifest Object Update: The documentation field in the manifest object now accepts a stringified array of objects in the format [{"title": "Your Title", "ipfsUrl": "QmZnLK4..."}]. This replaces the previous format with a reference to a single documentation file.
• New documentationSettings in package.json: You can now define documentationSettings in package.json, using the format [{"title": "Your Title", "filePath": "README.md"}]. You can now define up to 10 different files.
• Backward Compatibility and CLI Behavior: In the absence of the documentationSettings field, the CLI operates as usual. However, the documentation will be published in the new format, which is now a stringified array.