markdown lint fix

Author: codingbandit

09_LangChain/README.md

@@ -21,5 +21,3 @@ When an incoming message is received, the retriever will vectorize the message a
 ## Lab 4 - Vector search and RAG using LangChain
 
 In this lab, you will learn to use LangChain to re-implement the RAG pattern introduced in Lab 3. Take note of the readability of the code and how easy it is to compose a reusable RAG chain using LangChain that queries the products vector index in Azure Cosmos DB MongoDB vCore.
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