docs(main): update router doc (#3722)

* docs: update router doc

* fix: comments

Author: caohuilin

packages/document/main-doc/docs/en/apis/app/runtime/router/router.mdx

@@ -107,6 +107,28 @@ function App() {
 }
 ```
 
+### useRouteError
+
+```ts
+export declare function useRouteError(): unknown;
+```
+
+`useRouteError` returns the nearest ancestor Route error。
+
+```tsx
+import { useRouteError } from '@modern-js/runtime/router';
+const ErrorBoundary = () => {
+  const error = useRouteError();
+  return (
+    <div>
+      <h1>{error.status}</h1>
+      <h2>{error.message}</h2>
+    </div>
+  );
+};
+export default ErrorBoundary;
+```
+
 ## Components
 
 ### Link