Add the ability to have multpile Custom Instructions

I use chatGPT for many different use cases. Sometimes I need it for coding help, sometimes to practice my Spanish and other times just to chat about nonsense. Each of these require a different set. on custom instructions and I have to write them from scratch or copy/paste them from a saved text file. It would be a lot more convenient if chatGPT could have multiple Custom Instructions that are saved and can be chosen at the beginning of each new chat.