Kiauhoku

Feature update!

Major updates:
1. Now supporting interpolation of up to 6D grids (thank you Amanda Ash for the use case!)
2. Added a utility and demo notebook to look at the lengths of the tracks in each grid. Useful for debugging EEP issues
3. Huge improvement to `gridsearch_fit`, which now uses the few closest models as starting points (credit lmariemorales)
4. New notebook to fit grids to RGB stars (credit lmariemorales and see Morales et al. 2025)
5. Added a new subpackage `extensions` with our first extension of the code by AstroAware to look at continuously habitable zones around stars
6. Fully customizable EEPs! (credit AstroAware, and solves 12 )

Bug fixes and minor improvements:
- Added some interpolation tests
- Fixed 5 keyerror in mcmc.ipynb
- Fixed 11 file naming error
- Fixed 6 (I think! let me know if this persists)

GitHub-generated changelog
* add comment by lmariemorales in https://github.com/zclaytor/kiauhoku/pull/4
* Updates for Morales et al. 2025 by zclaytor in https://github.com/zclaytor/kiauhoku/pull/13
* Added HZ calculation module by AstroAware in https://github.com/zclaytor/kiauhoku/pull/10
* Tweaks to the HZ calc additions by zclaytor in https://github.com/zclaytor/kiauhoku/pull/14
* Merge feature update (dev 2.1.0 into main) by zclaytor in https://github.com/zclaytor/kiauhoku/pull/15

New Contributors
* lmariemorales made their first contribution in https://github.com/zclaytor/kiauhoku/pull/4
* AstroAware made their first contribution in https://github.com/zclaytor/kiauhoku/pull/10

**Full Changelog**: https://github.com/zclaytor/kiauhoku/compare/v2.0.0...v2.1.0

NOTE: This version is backwards compatible with the Google Colab notebook included with v1.4.0. The syntax, operation, and output remain the same. v1.4.0 is now therefore deprecated in favor of v2.0.0.

This has been the working version of kiauhoku for a while, but now it's official!

2024/03/25 NOTE. This version was created to work with the notebook listed below. However, the frozen dependencies now break Google Colab, so this version is deprecated in favor of v2.0.0.

This is the version of kiauhoku used in [Tayar, Claytor, et al. (2022)](https://ui.adsabs.harvard.edu/abs/2022ApJ...927...31T/abstract).
In particular, the Python Jupyter notebook `notebooks/model_offsets.ipynb` in this release demonstrates use of the `kiauhoku.StarGridInterpolator.gridsearch_fit` method used in the paper. Open the notebook in Google Colab (click the badge in the notebook) to try it for yourself!