templates[patch]: Add cohere librarian template (#14601)
Adding the example I build for the Cohere hackathon.
It can:
use a vector database to reccommend books
<img width="840" alt="image"
src="https://github.com/langchain-ai/langchain/assets/144115527/96543a18-217b-4445-ab4b-950c7cced915">
Use a prompt template to provide information about the library
<img width="834" alt="image"
src="https://github.com/langchain-ai/langchain/assets/144115527/996c8e0f-cab0-4213-bcc9-9baf84f1494b">
Use Cohere RAG to provide grounded results
<img width="822" alt="image"
src="https://github.com/langchain-ai/langchain/assets/144115527/7bb4a883-5316-41a9-9d2e-19fd49a43dcb">
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Co-authored-by: Erick Friis <erick@langchain.dev>
