:gear: added a prettier format config

vue-theme/package.json

@@ -64,5 +64,13 @@
     "plugins": [
       "@babel/plugin-syntax-dynamic-import"
     ]
+  },
+  "prettier": {
+    "trailingComma": "all",
+    "tabWidth": 4,
+    "semi": false,
+    "singleQuote": true,
+    "bracketSpacing": true,
+    "arrowParens": "avoid"
   }
 }