New
- Retain selected elements' original values using `--keep <tag_name>`.
The argument may be repeated to retain multiple elements' values.
Elements are identified by name (e.g. "PatientName", "StudyDate") or by
hexadecimal tag value (e.g. "0010,0010"). ([155](https://github.com/blairconrad/dicognito/issues/155))
- `Anonymizer.add_element_handler` allows addition of new element handlers (even custom ones)
to override existing behavior. ([155](https://github.com/blairconrad/dicognito/issues/155))
- New element handler type `dicognito.value_keeper.ValueKeeper` that will
keep element values as-is. ([155](https://github.com/blairconrad/dicognito/issues/155))
- New `--what-if` flag shows intended anonymization actions (as appear in the project README)
([163](https://github.com/blairconrad/dicognito/issues/163))
Fixed
- `--output-directory` may create duplicate anonymized files ([161](https://github.com/blairconrad/dicognito/issues/161))
Additional Items
- Format code using [Ruff](https://ruff.rs/) ([#156](https://github.com/blairconrad/dicognito/issues/156))