start configuring gulp's post-LESS css build-out task (see message)
-install gulp tasks (uncss, minify-css, css-lint and concatCSS)
-update package.json after listing those tasks as devDependencies
-create gulp "css_build" task that runs all those tasks
-move unminified styles.css to "css-build/"
-add minified core stylesheet to "build/css/"
remove unminified style.css from "css/build/"