Datasette-jellyfish

- Removed support for the `porter_stem()` function, which is no longer supported by the underlying [jellyfish](https://github.com/jamesturk/jellyfish) library. [#6](https://github.com/simonw/datasette-jellyfish/issues/6)

- Fixed a dependency issue by pinning to [jellyfish 0.9.0](https://jamesturk.github.io/jellyfish/changelog/#090-7-january-2021), the last version to include the `porter_stem` function. Thanks, [Eric Xanderson](https://github.com/disarticulate). [#6](https://github.com/simonw/datasette-jellyfish/issues/6)

- Updated README examples to reflect function name changes in version 1.0. [3](https://github.com/simonw/datasette-jellyfish/issues/3)

Renamed two functions for compatibility with the latest Jellyfish - see [their documentation](https://jellyfish.readthedocs.io/en/latest/comparison.html#jaro-similarity) for details.

* `jaro_distance(a, b)` is now `jaro_similarity(a, b)`
* `jaro_winkler(a, b)` is now `jaro_winkler_similarity(a, b)`