Comprehensive README improvements with examples and troubleshooting

- Added table of contents for easy navigation
- Expanded installation section with multiple methods and supported frameworks
- Created comprehensive authentication section covering all auth types
- Added detailed examples for all core operations:
  * Catalog operations with pagination
  * Tag operations including ListTagsByDigests
  * Manifest operations with full history access (addresses #14)
  * Blob operations (download, check, delete)
  * Blob upload operations (monolithic, chunked, mounting)
- Added real-world scenarios (copy images, download layers, cleanup)
- Added registry-specific examples (Docker Hub, ACR, ECR, Harbor, GitLab, local)
- Added configuration and advanced topics (HttpClient, certificates, tracing, proxy)
- Added comprehensive error handling section with retry patterns
- Added troubleshooting section addressing:
  * Issue #28: Provenance-enabled images
  * Issue #27: 405 authentication errors
  * Issue #14: Reading full manifest data
  * Common SSL, timeout, and 401 errors
- Added complete API reference for all operations
- Added migration guide from v1.x to v2.x
- Improved contributing and licensing sections

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Jaben