Improve GitHub documentation and public discoverability

[calliopeplugins-cloud]

Summary

• Updates the public GitHub README with verified product information.
• Improves repository discoverability with clearer public documentation.
• Keeps changes limited to documentation and public presentation.

Safety

• No plugin PHP, JavaScript, CSS, readme.txt, version, slug, text domain, namespace, or license changes.
• No Pro repository links or private implementation details added.
• No releases or tags created.

Validation

• git diff --check
• README link check for public URLs
• Secret-pattern scan against README.md