Rig 0.19 released!

[joshua-mo-143]

Hi everyone, I'd like to officially announce that Rig 0.19 is available!

New features

• We've added a new ChatbotBuilder struct to help you write CLI chatbots that can use multi-turn. Insert the agent of your choice (and how many turns you want to use), and you'll be all set.
• Multi-turn streaming is now Send + 'static. You can now use it in whatever web framework you'd like!
• Streams can now be optionally paused. You may need to increase HTTP client timeout if you are pausing for an extended period of time.
• New ConvertMessage trait to help you get around the orphan rule for implementing providers in your own crates.

Bug fixes

• Fixed a bug in Gemini causing Vec<T> to not convert properly for the Schema.
• Fixed a bug where OpenAI Responses API requires additionalProperties to be set for every struct in a schema but it wasn't being set
• Fixed function calls not working with reasoning models on OpenAI Responses API

Other

• Some duplicate methods removed
• Some very minor docs changes (to fix wording)
• We have overhauled the docs.rs site to make every item with trait bounds more readable, as well as adding all feature gated items to the docs

Happy building! We build rig, rig builds us.

Check out the full changelog: #729