add devDep

Author: nicolethoen

package-lock.json

@@ -68,6 +68,7 @@
     "jest": "^29.7.0",
     "jest-canvas-mock": "^2.5.2",
     "jest-environment-jsdom": "^30.2.0",
+    "mini-css-extract-plugin": "^2.10.2",
     "postcss": "^8.5.8",
     "prettier": "3.5.3",
     "react": "^18",