pencil2d/pencil — reverse-engineered prompt

Build me an easy desktop app for making 2D hand drawn animations, like a simple animation studio for beginners. I want people to be able to draw cartoons frame by frame, use both bitmap and vector artwork, organize drawings on a timeline, preview the animation, and keep the interface clean enough that a new user can figure it out without a long tutorial.

It should work on Windows, macOS, Linux, and FreeBSD if possible. Include the basic drawing tools someone expects, like pencil, brush, eraser, colors, layers, and a way to flip through frames while drawing. Add a small help or quick reference section inside the app so users can learn the main tools quickly.

Please make it feel lightweight, friendly, and focused on traditional hand drawn animation instead of a complicated professional suite. Use the existing repo direction and look up current docs online if you need to.