docs: Integrations LangChain code fix (#378)

Author: LaverdeS

docs/source/integrations.rst

@@ -45,6 +45,7 @@ Our integration with `LangChain <https://github.com/hwchase17/langchain>`_ makes
 To use ``Unstructured.io File Loader`` you will need to have LlamaIndex 🦙 (GPT Index) installed in your environment. Just ``pip install llama-index`` and then pass in a ``Path`` to a local file. Optionally, you may specify split_documents if you want each element generated by ``unstructured`` to be placed in a separate document. Here is a simple example on how to use it:
 
 .. code:: python
+
   from pathlib import Path
   from llama_index import download_loader