fix: export useRouter back

Closes #39

Author: sergeysova

src/index.tsx

@@ -1,6 +1,6 @@
 export { Link, type LinkProps } from "./link";
 export { Route, type RouteProps } from "./route";
-export { RouterProvider, type RouterProviderProps } from "./router-provider";
+export { RouterProvider, type RouterProviderProps, useRouter } from "./router-provider";
 export { createRouteView, type RouteViewConfig } from "./create-route-view";
 export { createRoutesView, type RouteRecord, type RoutesViewConfig } from "./create-routes-view";
 export { useLink } from "./use-link";