update reactrouter url

Author: zongben

src/content/learn/build-a-react-app-from-scratch.md

@@ -83,7 +83,7 @@ Routers are a core part of modern applications, and are usually integrated with
 
 We suggest using:
 
-- [React Router](https://reactrouter.com/start/framework/custom)
+- [React Router](https://reactrouter.com/home)
 - [Tanstack Router](https://tanstack.com/router/latest)