Wrong `chat_format` documented for Moondream 2

Hi! 👋

I was testing the Server API with Moondream 2 as the model, and the [documented `chat_format`](https://github.com/abetlen/llama-cpp-python/blob/37eb5f0a4c2a8706b89ead1406b1577c4602cdec/README.md#L504), `moondream2`, threw an error:

```plain
Error code: 500 - {'error': {'message': "Invalid chat handler: moondream2 (valid formats: ['llama-2', 'llama-3', 'alpaca', 'qwen', 'vicuna', 'oasst_llama', 'baichuan-2', 'baichuan', 'openbuddy', 'redpajama-incite', 'snoozy', 'phind', 'intel', 'open-orca', 'mistrallite', 'zephyr', 'pygmalion', 'chatml', 'mistral-instruct', 'chatglm3', 'openchat', 'saiga', 'gemma', 'functionary', 'functionary-v2', 'functionary-v1', 'chatml-function-calling'])", 'type': 'internal_server_error', 'param': None, 'code': None}}
```

[Looking at the code](https://github.com/abetlen/llama-cpp-python/blob/37eb5f0a4c2a8706b89ead1406b1577c4602cdec/llama_cpp/server/model.py#L118), it appears that the correct `chat_format` is `moondream` and not `moondream2` (`moondream` worked as expected).

What do you think?

Let me know if I can open a PR to fix the documented `chat_format`, please.

Thank you for this project! 😄