Guide: Chat bot application example using langchain4j-cdi and RAG

[yersan]

Add an example of a Chat bot application describing how to integrate with an LLM using langchaing4j-cdi, add simple RAG capabilities and use infinispan web cache to control LLM memory

[yersan]

offloading the messages to infinispan is still a bit unclear to me, so I will left it to a follow up guide