refactor: Move internal documentation to external docs directory

Relocated non-customer-facing documentation from repository root
to /Users/mkreyman/workspace/docs/mcp-memory-keeper/ for better organization:

- Testing reports → docs/mcp-memory-keeper/testing-reports/
- Implementation reports → docs/mcp-memory-keeper/implementation-reports/
- QA reports → docs/mcp-memory-keeper/qa-reports/

Keeps repository clean with only customer-facing docs:
- README.md, API.md, EXAMPLES.md, RECIPES.md (retained)
- ARCHITECTURE.md, TROUBLESHOOTING.md (retained)
- CONTRIBUTING.md, CHANGELOG.md (retained)

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

Co-Authored-By: Claude <[email protected]>

Author: mkreyman