docs: complete Docker documentation migration to wiki

- Remove DOCKER_STRATEGY.md and DOCKER_CHANGES.md from main repository
- Update wiki submodule with comprehensive English Docker documentation
- Consolidate all Docker-related information in centralized wiki

The Docker documentation is now available in English at:
https://github.com/JohanDevl/Export_Trakt_4_Letterboxd/wiki/Docker

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

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

Author: JohanDevl