Adds hyde prompts for Ask ChatGPT command

[kristenbrann]

https://arxiv.org/pdf/2212.10496.pdf

When you ask chatgpt a question, now we:

• ask chatgpt to generate a markdown note that would answer the question via completions
• parse the note chatgpt writes into blocks
• generate embeddings for the hyde note, all its blocks, and the original question
• compare vectors for all of the above to vectors from your vault
• use the top 8 matches as context for your question to chatgpt