feat: separate indexes and PineconeIndex

Using index.describe instead of shape[].

The RouteLayer.categories() attribute has been removed, removing parts that reference this attribute form the tests.

RouteLayer.remove() renamed to delete().

Merge branch 'indices_classes' of https://github.com/aurelio-labs/semantic-router into indices_classes

Mostly just trying to make MyPy happy!

feat: Added support for MistralAI API. This includes a

Rather than is_index_populated.

installed poetry and ran make.  added mistralai to the pyproject.toml (first time using poetry, nice tool)

fix: issue #94 added from clause to the exception statement in

the __call__ method of the Zure class to make it more informative

new encoder and a new LLMS. The encoder is a
simple wrapper around the MistralAI API, and the
LLMS is a simple wrapper around the encoder.
The encoder is tested with a simple unit test,
and the LLMS is tested with a simple unit test.

It's defined in the BaseIndex which LocalIndex inherits anyway

Also fixed bug in layer.py where we weren't:
a) Setting the index_name to a default value.
b) Weren't using index_name.

Making pydantic leave me alone and giving the correct index name.