Refresh README and trust publisher setup guidance

[Markeljan]

Summary

• Rework README to speak to end users, add Bun-based install instructions, configuration/setup guidance, and common flags so the npm page feels polished.
• Document how to handle access tokens, refresh cycles, and trusted publisher requirements so publishing steps are clearer.
• Tie the package back to this repository by highlighting the GitHub link and workflow/release details for richer npm metadata.

Testing

• Not run (not requested)