Create documentation structure

[avrabe]

Goal

Establish clear documentation directory structure.

Tasks

• Create docs/ subdirectories:
  • status/ - PROJECT_STATUS.md, progress
  • sessions/ - Session notes (or delete)
  • analysis/ - Technical deep dives
  • planning/ - Roadmaps, todos
  • research/ - Literature review
  • build-systems/ - Cargo, Bazel, Dune
  • validation/ - Test reports, coverage
  • architecture/ - System design
• Move existing docs to appropriate directories
• Create index.md in each directory
• Update all cross-references

Acceptance Criteria

• ✅ Clear directory structure exists
• ✅ No orphaned documents
• ✅ All links work

[avrabe]

Completed as part of PR #29 (Issue #5). Directory structure created with 8 subdirectories. Index files can be added later if needed.