Update package.json

Author: masx200

package.json

@@ -13,6 +13,7 @@
     "scripts": { "format": "prettier --w */*/*.yml */*.yml *.xml" },
     "keywords": [],
     "devDependencies": {
-        "prettier": "^2.8.8"
+        "prettier": "^2.8.8",
+        "@prettier/plugin-xml":"2.2.0"
     }
 }