new_site/purgecss.config.js

module.exports = {
    content: [
        "_site/**/*.html",
        "_site/**/*.js"
    ],
    css: [
        "_site/assets/css/*.css"
    ],
    output: "_site/assets/css/",
    skippedContentGlobs: [
        "_site/assets/**/*.html"
    ]
};