- Updated `plus7rotation` and `minus7rotation` functions to initialize DataFrames with specified columns and types.
- Enhanced error handling in `train_nn.py` to check for empty training, validation, and test datasets.
- Added preprocessing capabilities in `generate_keypoints.py` to apply darkening and brightening effects on videos.
- Introduced `combine_datasets.py` to merge two datasets into one folder.
- Created `darken_dataset.py` to generate darkened copies of videos with configurable parameters.
- Implemented a FastAPI application in `app.py` for real-time sign language prediction.
- Added a user interface in `index.html` for webcam recording and video upload.
- Updated model loading in `evaluate.py`, `train_nn.py`, and `inference.py` to support new checkpoint formats.
- Introduced `video_preprocess.py` for video frame processing with darkening and brightening functions.
