Add JSDoc comments for public-facing API

[hatemhosny]

• I'm submitting a ...

  • [ ] bug report
  • [x] feature request
  • [ ] question about the decisions made in the repository
  • [ ] question about how to use this project

• Summary

Add JSDoc comments, with descriptions, usage guides, examples, code samples and links to docs.

This can significantly improve the developer experience for the library users.

Most of the content can be found in the docs