fix vite-plugin-node-polyfills error

Author: abentkamp

Diff for: README.md

@@ -47,8 +47,10 @@ For some reason, the file (here `test.lean`) cannot be at the root of the file s
 The package uses the Lean 4 VSCode extension, which is intended to run in a nodejs runtime. Therefore, we need to install node polyfills.
 Here is how this can be done if your project uses Vite:
 ```
-npm install vite-plugin-node-polyfills memfs 
+npm install [email protected] --save-exact
+npm install memfs 
 ```
+(We use version 0.17.0 due to this bug: https://github.com/davidmyersdev/vite-plugin-node-polyfills/issues/81)
 
 ```ts
 // vite.config.ts

Diff for: demo/package-lock.json

@@ -29,7 +29,7 @@
     "eslint-plugin-react-refresh": "^0.4.7",
     "typescript": "^5.2.2",
     "vite": "^5.3.1",
-    "vite-plugin-node-polyfills": "^0.22.0",
+    "vite-plugin-node-polyfills": "=0.17.0",
     "vite-plugin-static-copy": "^1.0.6"
   }
 }