message: add dist:css run-script, do it postdist + prebuild
diff: "module": "dist/index.esm.js",
  "scripts": {
  "dev": "next dev",
  + "prebuild": "npm run dist:css",
  "build": "next build",
  "start": "next start",
  "predist": "rm -rf dist",
  "dist": "NODE_ENV=production rollup -c",
  - "postdist": "primer-module-build src/primer-react.scss --outputDir dist/css",
  + "postdist": "npm run dist:css",
  + "dist:css": "node-sass --include-path node_modules --output-style compressed src/primer-components.scss -o dist",
  "prepack": "script/npm-pack-check",
  "prepublishOnly": "npm run dist",
  "lint": "eslint src pages",
  