- Added `--clip-ct LO HI` argument to clip CT intensities before registration and scoring, improving A/B comparisons.
- Implemented `_clip_image` function to handle intensity clipping of images.
- Updated registration functions to utilize CT clipping where beneficial, specifically in `register_niftyreg` and `register_synthmorph`.
- Enhanced `fixed_moving` function to ensure CT is always treated as the fixed image.
- Introduced Docker support for NiftyReg v2.1.1, including a Dockerfile for building the image.
- Updated documentation and help messages to reflect new features and usage instructions.
- Adjusted evaluation criteria for registration quality to account for intensity clipping.
