* only run Lightning CSS when passing `--minify` to the CLI
* only optimize the CSS when creating a production build
* add `optimize` option to PostCSS plugin
- The optimize option can be set to `true`, which will optimize
(unnesting, adding browser prefixes, lowering values) and minify
- The optimize option can also be set to `{ minify: false }`, which will
optimize but not minify.
* default `optimize` option to the true for `NODE_ENV=production`
* add `--optimize` flag to CLI
This will only optimize the CSS output without minification.
* update `--minify` description
* update changelog
* move `cli` to its own package `@tailwindcss/cli`
* minify builds when using `tsup`
* prefer tsup cli flag over tsup.config.ts file
* add `--clean`, to make sure `dist/` folders are cleaned before building
* make CLI esm only
* use version of `tailwindcss` instead of the version of `@tailwindcss/cli`
