Remove deprecated files and enhance documentation
- Deleted `coverage.sh`, `docker-compose.yaml`, `Dockerfile`, and simulator-related files to streamline the project structure.
- Updated `README.md` to provide a comprehensive overview of the OPC Ingestor, including features, architecture, installation, usage, and troubleshooting.
- Enhanced docstrings across various classes and methods in the `ingestor` module for better clarity and maintainability.
- Improved Prometheus metrics documentation in `metrics.py` to ensure proper monitoring and observability of the system.
