Added support for deepseek LLMs

[Riddhimaan-Senapati]

I have added code to support the deepseek suite of LLMs along with testing code. I used the current implementations of the openAI providers and Groq providers as inspiration.

This partially solves issue #140

[Riddhimaan-Senapati]

@ksolo @foxty @jeffxtang @joaomdmoura Can anyone of you review my PR please?

[ksolo]

@Riddhimaan-Senapati I will take a look at this later today.

[ksolo]

@Riddhimaan-Senapati can you add a guide similar to the other providers in the guides directory - https://github.com/andrewyng/aisuite/tree/main/guides

[Riddhimaan-Senapati]

@Riddhimaan-Senapati can you add a guide similar to the other providers in the guides directory - https://github.com/andrewyng/aisuite/tree/main/guides

Done. I have added a DeepSeek guide in the guides directory.

[ksolo]

I'll do a manual test of this tomorrow and provided that goes well, we'll get this merged. Thank you!

[JiaLiangC]

DeepSeek v3 is really both affordable and user-friendly.

[Riddhimaan-Senapati]

@ksolo Were you able to test it?

[ksolo]

@Riddhimaan-Senapati Sorry I've been pulled into a few things lately that had to take priority. I can get to this over the weekend.