feat: Added support for MistralAI API. This includes a

[dwmorris11]

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.

[codecov]

Codecov Report

Attention: 10 lines in your changes are missing coverage. Please review.

Comparison is base (43f9808) 90.84% compared to head (b8a899f) 90.65%.

Files	Patch %	Lines
semantic_router/llms/mistral.py	82.85%	6 Missing ⚠️
semantic_router/encoders/mistral.py	95.00%	2 Missing ⚠️
semantic_router/schema.py	60.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #142      +/-   ##
==========================================
- Coverage   90.84%   90.65%   -0.20%     
==========================================
  Files          29       31       +2     
  Lines        1322     1402      +80     
==========================================
+ Hits         1201     1271      +70     
- Misses        121      131      +10     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[dwmorris11]

Performed all the tests after learning how to use poetry. Appears ready for merge.

[jamescalam]

nice, this looks great @dwmorris11 — I've merged, will be included in the next release (should be published in the next few days)