text: [download] 100% of  134.98MiB    [ExtractAudio] Not converting audio /Users/31treehaus/Desktop/AI/langchain-fork/docs/modules/indexes/document_loaders/examples/The spelled-out intro to neural networks and backpropagationï¼š building micrograd.m4a; file is already in target format m4a# Returns a list of Documents, which can be easily viewed or parseddocs[0].page_content[0:500]    "Hello, my name is Andrej and I've been training deep neural networks for a bit more than a decade. And in this lecture I'd like to show you what neural network training looks like under the hood. So in particular we are going to start with a blank Jupyter notebook and by the end of this lecture we will define and train a neural net and you'll get to see everything that goes on under the hood and exactly sort of how that works on an intuitive level. Now specifically what I would like to do is I w"Building a chat app from YouTube videoâ€‹Given Documents, we can easily enable chat / question+answering.from langchain.chains import RetrievalQAfrom langchain.vectorstores import FAISSfrom langchain.chat_models import ChatOpenAIfrom langchain.embeddings import OpenAIEmbeddingsfrom langchain.text_splitter import RecursiveCharacterTextSplitter# Combine doccombined_docs = [doc.page_content for doc in docs]text = " ".join(combined_docs)# Split themtext_splitter = RecursiveCharacterTextSplitter(chunk_size=1500, chunk_overlap=150)splits = text_splitter.split_text(text)# Build an indexembeddings = OpenAIEmbeddings()vectordb = FAISS.from_texts(splits, embeddings)# Build a QA chainqa_chain = RetrievalQA.from_chain_type(