added langchain app for simplicity

langchainapp.py

@@ -95,7 +95,7 @@ class MyEmbeddingFunction(EmbeddingFunction):
         # query_prefix = "Instruct: " +tasks[selected_task] +"\nQuery: "  
         # Construct the embed_instruction and query_instruction dynamically  
         embed_instruction = f"Instruct: {task_description}" +"\nQuery:"  
-        query_instruction = f""  
+        # query_instruction = f""  
           
         # Update the hf_embeddings object with the new instructions  
         self.hf_embeddings.embed_instruction = embed_instruction