It's important that you create a CSS file that people can import in their project if they use your package. There are a couple of steps involved to do this.

1. Create a tailwind.config.js file

module.exports = {
  content: ["./src/**/*.{ts,tsx}"],
  theme: {
    extend: {},
  },
  plugins: [],
};

2. Install some devDependencies:

yarn add -D tailwindcss tsc-watch

3. Add this to your package.json scripts

{
  "dev": "npx tsc-watch --onSuccess 'yarn css'",
  "css": "tailwindcss -o css.css"
}

That's it!