Release Candidate v0.3.0-rc.1 is published!

[brainlid]

See the CHANGELOG for details on the breaking changes and how to update existing code.

There have been a LOT of fixes and new features in this release thanks to the many contributions!

Some of the features I'm most excited about:

• A new SummarizeConversationChain takes another LLMChain and all it's messages and summarizes and removes the summarized messages. This makes it easier to have long conversations while having more control over the context window and total input token count.
• The LLMChain.run/2 has a new option called with_fallbacks: [...] which allows your LLMChain to fallback to a different model when one is unavailable. This is an important feature for production systems that want uninterrupted service while OpenAI, Anthropic, or other LLM is "down" or "overloaded" or something.
• Updated docs for ChatOpenAI showing how to use it with Azure Open AI hosted models.
• The TextToTitleChain now supports overriding the system prompt for better control