Annoy

TODO
----

* Wheel

- Refactor native extension codes to set rb_data_type_t.wrap_struct_name for each metric and dtype.

- Fix bug that item elements are converted to unsingned integers when dtype is set to float32 ([3](https://github.com/yoshoku/annoy-rb/issues/3)).

- Update bundled Annoy version to 1.17.1.
- Refactor config files.

- Refactor codes and configs with RuboCop and clang-format.

- Add `dtype` argument to initialize method to specify the data type of vector element.
If you want to load a search index created with the Python bindings, specify 'float32' to the dtype argument.


require 'annoy'

f = 40
t = Annoy::AnnoyIndex.new(n_features: f, metric: 'angular', dtype: 'float32')
t.load('index_with_python_bindings.ann')


- Change the data type of item index from int to int32_t.
- Update type declarations and documentations.
- Introduce conventional commits.