In some environments, depending on the Node version importing a `.json`
file without a `with` or `assert` doesn't work.
Let's play it safe and use an `fs.readFileSync` instead.
* 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`
