Format during extract

dan/datasets/__init__.py

dan/datasets/extract/__init__.py

dan/datasets/extract/extract.py

dan/datasets/extract/utils.py

dan/datasets/format/__init__.py

docs/get_started/training.md

docs/ref/datasets/format/atr.md

docs/ref/datasets/format/index.md

docs/usage/datasets/extract.md

docs/usage/datasets/format.md

docs/usage/datasets/index.md

mkdocs.yml

tests/test_extract.py

tests/test_format.py