obarlik/banner-maker ? reverse-engineered prompt

Build me a Python tool that makes polished project banners for GitHub README files.

I want to be able to give it a title, subtitle, and optional logo, then generate a clean banner image with modern styling. It should support custom colors, gradients, patterns, shapes, textures, and a few visual effects so I can make different looks without editing images by hand. If possible, make it smart about sizing the text and choosing colors that still look readable.

I also want a simple command line experience, so I can run one command to make a banner, or choose from a bunch of ready made presets for different styles. It would be great if it can also generate a demo sheet with several variations so I can compare designs quickly.

Please make the output a nice PNG sized for README use, and include a few example commands so I can try it right away. If you need to check current library docs online, feel free to do that.