Add enhanced AI attribution support with documentation and RSS feed configuration

[amiable-dev]

This PR enhances the AI attribution functionality by adding documentation, templates, and RSS feed support.

Changes

1. Documentation:

   • Added comprehensive AI attribution guidelines
   • Created template for AI-generated posts
   • Added clear examples and standards

2. Authors Configuration:

   • Updated image and URL paths in authors.yml
   • Added fallback image support
   • Fixed HTTPS URLs

3. RSS Feed:

   • Added custom feed item creation
   • Marks AI-generated content in feed
   • Preserves metadata in feed

Testing Checklist

• Verify AI attribution guidelines are clear and complete
• Test post template with new content
• Check RSS feed displays AI attribution correctly
• Verify fallback images work
• Test documentation links and examples

Documentation Updates

• New file: docs/contributing/ai-attribution.md
• New template: .github/TEMPLATES/ai-post-template.md
• Updated RSS feed configuration

Future Considerations

• Analytics for AI-generated content
• Enhanced metadata display in RSS
• Automated validation of AI attribution

This builds on the author attribution changes from PR #33 and provides a complete framework for AI content management.