Velvet transformer to minify CSS class names

<div class='red'>Red color</div>
<div class='blue'>Blue color</div>

<style>
	.red {
		color: red;
	}

	.blue {
		color: blue;
	}
</style>

<div class='a'>Red color</div>
<div class='b'>Blue color</div>

<style>
	.a {
		color: red;
	}

	.b {
		color: blue;
	}
</style>