Most of OpenAI’s changes to ChatGPT involve what the AI-powered bot can do: questions it can answer, information it can access, and improved underlying models. This time, though, it’s tweaking the way you use ChatGPT itself. The company is rolling out a new version of the service that allows you to prompt the AI bot not just by typing sentences into a text box, but by either speaking aloud or just uploading a picture. The new features are rolling out to those who pay for ChatGPT in the…