Add Phase 3 tutorials with audience targeting (#94)
## Summary
- Create tutorials directory structure with index page
- Add 5 main tutorials targeting different audiences:
- **what-is-blumeops** (Reader, AI) - High-level orientation
- **exploring-the-docs** (All) - Navigation guide
- **ai-assistance-guide** (AI, Owner) - Context for AI-assisted operations
- **contributing** (Contributor) - First contribution workflow
- **replicating-blumeops** (Replicator) - Overview for building similar setup
- Add 4 replication sub-tutorials:
- tailscale-setup, kubernetes-bootstrap, argocd-config, observability-stack
- Update README.md to mark Phase 3 complete
- Add changelog fragment
Each tutorial explicitly identifies its target audiences and links to reference material rather than re-explaining concepts.
## Deployment and Testing
- [x] All pre-commit hooks pass (doc-links validates wiki links)
- [ ] Build docs via workflow to verify rendering
- [ ] Review content for accuracy
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/94
Erich Blume
7ebac4aef6