stylelint: 13 -> 14
postcss-preset-env: 6 -> 7
eslint-plugin-compat: 3 -> 4
replaced stylelint-config-standard with
stylelint-config-standard-scss
switched to @ronilaukkarinen/gulp-stylelint, a fork of gulp-stylelint,
due to the upstream's maintainer going missing
temporarily disabled some stylelint rules to ease transition