Buzz around GPT-4, the anticipated but as-yet-unannounced follow-up to OpenAI’s groundbreaking large language model, GPT-3, is growing by the week. But OpenAI is not yet done tinkering with the previous version. The San Francisco-based company has released a demo of a new model called ChatGPT, a spin-off of GPT-3 that is geared toward answering questions…