✨ [Feature]: add llms.txt.

[hu-qi]

Below you can find a list of documentation files in the llms.txt format, specifically llms.txt and llms-full.txt. These files allow large language models (LLMs) and agents to access programming documentation and APIs, particularly useful within integrated development environments (IDEs).

readmore:

• https://langchain-ai.github.io/langgraph/llms-txt-overview/
• https://llmstxt.org/