chore: add relative path and watch to html and react playgrounds

[pawelphilipczyk-cloudinary]

Pull request for cloudinary/frontend-frameworks

For which package is this PR?

• @cloudinary/react
• @cloudinary/html

What does this PR solve?

• Adds possibility to run watch in @cloudinary/html and @cloudinary/react packages
• Uses relative file: dependencies in react and html playgrounds to refresh on build change

Final checklist

• [ ] Implementation is aligned to Spec.
• [ ] Tests - Add proper tests to the added code.
• [ ] Relates to a github issue (link to issue).