lipis/flag-icons ? reverse-engineered prompt

Build me a simple website and asset library for country flags, with a clean demo page where I can browse flags and see how to use them in code.

I want the project to include SVG flags for countries, along with ready to use CSS classes so someone can drop a flag into an app with a small span and a country code like gr or gb. Please also include a square version option and make sure the styling works nicely inline with text or inside other elements. If it helps, use the current docs online for any tricky parts.

Make the homepage feel like a useful showcase, with a few examples, clear usage instructions, and an easy way to understand how to install it with npm or a CDN. Keep it polished, lightweight, and friendly for developers, but simple enough that someone skimming the page can get started fast.