Increase training stability and avoid timeout caused by OpenAI API calling rate limit

[EricGao888]

• For users without pro accounts, requests to OpenAI API frequently time out due to calling rate limit.
• We could add a retry policy to increase stability.
  

  DocsGPT/scripts/parser/open_ai_func.py

  Lines 25 to 43 in 5883ce2

  	for i in tqdm(docs, desc="Embedding 🦖", unit="docs", total=len(docs), bar_format='{l_bar}{bar}| Time Left: {remaining}'):
  	try:
  	import time
  	store.add_texts([i.page_content], metadatas=[i.metadata])
  	except Exception as e:
  	print(e)
  	print("Error on ", i)
  	print("Saving progress")
  	print(f"stopped at {c1} out of {len(docs)}")
  	faiss.write_index(store.index, "docs.index")
  	store_index_bak = store.index
  	store.index = None
  	with open("faiss_store.pkl", "wb") as f:
  	pickle.dump(store, f)
  	print("Sleeping for 60 seconds and trying again")
  	time.sleep(60)
  	faiss.write_index(store_index_bak, "docs.index")
  	store.index = store_index_bak
  	store.add_texts([i.page_content], metadatas=[i.metadata])

[EricGao888]

BTW, adding a retry policy will significantly reduce the chance of getting into the exception handling logic and will be a workaround for #55