downgrade demo to react 18

Author: harrel56

examples/package.json

@@ -22,7 +22,7 @@
     "@babel/preset-typescript": "7.26.0",
     "@types/jest": "29.5.14",
     "@types/react": "18.3.20",
-    "@types/react-dom": "19.0.4",
+    "@types/react-dom": "18.3.5",
     "@types/sortablejs": "1.15.8",
     "@types/prismjs": "1.26.5",
     "jest": "29.7.0",