add: example for tanstack start

examples/tanstack-start/src/router.tsx

@@ -0,0 +1,17 @@
+import { createRouter } from '@tanstack/react-router'
+
+// Import the generated route tree
+import { routeTree } from './routeTree.gen'
+
+// Create a new router instance
+export const getRouter = () => {
+  const router = createRouter({
+    routeTree,
+    context: {},
+
+    scrollRestoration: true,
+    defaultPreloadStaleTime: 0,
+  })
+
+  return router
+}