Resolve Issue #14, update deprecation of BaseChatModel.predict, update setup process

fix: resolves issue #14
fix: typos first mentioned in PR: #11
fix: add missing OPENAI_API_KEY setup in query_data.py as mentioned in PR: #13
fix: update the deprecation of the method BaseChatModel.predict as mentioned in PR: #15
feature: update the setup process to include downloading on missing NLTK tokenizers, setup of local .env file, and the requirement of OpenAI needing money on your account

pixegami / langchain-rag-tutorial