README.ko.md: sync with English README redesign

Full Korean translation of the redesigned README:
- ASCII memory diagram and quality charts
- Engine comparison table (vs llama.cpp/vLLM/MLX/ONNX)
- Collapsible FAQ and architecture details
- Updated model table with speed + compression
- Centered layout with badge row

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: unamedkr