Prevent caching in startOver() function

As the use of the `forceget` parameter in `window.location.reload()`
isn't supported in most browsers[1], a query string must be appended to the
location URL when refreshing the page. This commit adds a query string
made up of random characters.

[1]: https://developer.mozilla.org/en-US/docs/Web/API/Location/reload#forceget

src/app/page.tsx

@@ -79,7 +79,8 @@ export default function Home() {
   }
 
   const startOver = () => {
-    window.location.reload();
+    window.location = location.href + "?start-over=" +
+      (Math.random() + 1).toString(36).substring(2)
   };
 
   return (