ESP32-S3-DevKit support

Hello, it's great. But for now, I'm working locally with a virtual machine.

I tried to follow the current Espruino organization and build system, but I couldn't do it. I have created a new folder structure and build system that fits with ESP-IDF 4.x.

So we can follow different paths:

• Share the code I have as it is, and each one sets up their own system.
  
• Create a repository, upload everything, and start working independently of Espruino at the begining..
  
• Try to unify with the current Espruino repository, but I don't have the knowledge and time for it.
  
  

Or any other option that is preferred, I can adapt.