LangChain v0.1.0

LangChain has released its first stable version, 0.1.0, which is fully backwards compatible and available in both Python and JavaScript. This release includes improved functionality and documentation to help developers build applications using large language models (LLMs). The new versioning standard ensures clear communication of any breaking changes and allows for the deprecation and deletion of old code. LangChain has also made significant improvements to third-party integrations, observability, composability, streaming, output parsing, retrieval, and agents. Future plans include rewriting legacy chains in LCEL, adding new types of chains and agents, improving production ingestion capabilities, and maintaining support for the 0.1 branch after the release of version 0.2.