docker/scout-cli ? reverse-engineered prompt

Build me a simple repo for Docker Scout CLI installation and usage.

I want it to help people install the docker scout plugin on Linux, macOS, and Windows, with a one command install script for macOS and Linux, and clear manual install steps too. It should explain how to place the binary in the right Docker plugin folder, make it executable when needed, and add the plugin directory to Docker config. Also include a short guide for running it as a container and examples for using it in CI, especially GitHub Actions and GitLab, so teams can check images for security issues and fail builds when critical problems are found.

Keep the docs easy to follow, with sensible defaults, environment variable options, and a clean README that feels like a real open source tool. If anything is unclear, look up the current Docker Scout docs online and match the setup to that.