Neo4j Advanced RAG template (#12794)

Todo:

- [x] Docs

templates/neo4j-advanced-rag/main.py

@@ -0,0 +1,10 @@
+from neo4j_advanced_rag.chain import chain
+
+if __name__ == "__main__":
+    original_query = "What is the plot of the Dune?"
+    print(
+        chain.invoke(
+            {"question": original_query},
+            {"configurable": {"strategy": "parent_document"}},
+        )
+    )