Llm-gemini

- Support for the `text-embedding-004` embedding model: `llm embed -m text-embedding-004 -c 'hello world'`. [7](https://github.com/simonw/llm-gemini/issues/7)

- Support for system instructions: `llm -m p15 'say hi three times three different ways' --system 'in german'`. [6](https://github.com/simonw/llm-gemini/issues/6)

- Added support for Gemini 1.5 Pro, for users with access to the API preview. Use that model with `llm -m gemini-1.5-pro-latest "prompt"`. [5](https://github.com/simonw/llm-gemini/issues/5)

- Initial prototype. [1](https://github.com/simonw/llm-gemini/issues/1)