Add Hindsight - AI agent memory by Vectorize

[nicoloboschi]

Summary

• Adds Hindsight to the list — state-of-the-art long-term memory for AI agents by Vectorize.
• Hindsight is open source (MIT-licensed), can run fully self-hosted, and integrates with popular agent frameworks including LangChain, CrewAI, LlamaIndex, Vercel AI SDK, and more.
• GitHub: https://github.com/vectorize-io/hindsight