Added
- "Label alignment" functionality for RGDR, to align labels over multiple train-test splits ([144](https://github.com/AI4S2S/s2spy/pull/144)).
- A preprocessing module, which can be used to calculate climatology/anomalies and to detrend data ([152](https://github.com/AI4S2S/s2spy/pull/152)).
- Support for specifying multiple target and precursor intervals in RGDR ([153](https://github.com/AI4S2S/s2spy/pull/153)).
Changed
- A bug in the spherical area calculation of RGDR has been fixed ([133](https://github.com/AI4S2S/s2spy/pull/133)).
- Default settings for RGDR have been removed. Users now need to fully specify their RGDR setup ([133](https://github.com/AI4S2S/s2spy/pull/133)).
- The RGDR visualization plots are now called using `RGDR.preview_correlation` and `RGDR.preview_clusters` ([106](https://github.com/AI4S2S/s2spy/pull/106)).
Removed
- Calendar, resampling, and traintest modules have been moved to a separate package named [Lilio](https://github.com/AI4S2S/lilio) ([#158](https://github.com/AI4S2S/s2spy/pull/158)).
Dev changes
- Use `hatch` as the project manager, and `ruff` as the linter ([159](https://github.com/AI4S2S/s2spy/pull/159)).
- Notebooks have been moved to the docs folder, to be included in ReadtheDocs in the future ([159](https://github.com/AI4S2S/s2spy/pull/159)).