Extend n8n guide with using (managed) Redis as vector store

[martin-helmich]

Redis 8.6 can now be deployed as a managed database in the mStudio, which can also be used as a Vector database.¹

Proposition:
Extend the RAG section of the n8n Guide (https://developer.mittwald.de/docs/v2/guides/apps/n8n/#rag-with-postgresql-and-mittwald-ai-hosting) by documenting how to use a mStudio managed Redis instance as vector store.

Footnotes

1. https://redis.io/docs/latest/develop/get-started/vector-database/ ↩