🎨 Improve development structure

package.json

@@ -7,9 +7,10 @@
   },
   "main": "bin/index.js",
   "scripts": {
-    "demo-folder": "cd test/demo-folder && node ../../bin 'Demo folder'",
+    "demo-folder": "cd test/demo-folder && node ../../bin 'Demo folder' --open false --test true",
     "site-dev": "node site/build/dev-server.js",
-    "site-build": "node site/build/build.js"
+    "site-build": "node site/build/build.js",
+    "dev": "npm-run-all --parallel demo-folder site-dev"
   },
   "repository": {
     "type": "git",
@@ -61,6 +62,7 @@
     "friendly-errors-webpack-plugin": "^1.1.3",
     "html-webpack-plugin": "^2.28.0",
     "http-proxy-middleware": "^0.17.3",
+    "npm-run-all": "^4.0.2",
     "opn": "^5.1.0",
     "optimize-css-assets-webpack-plugin": "^2.0.0",
     "ora": "^1.2.0",