fix(docs): update tanstack start routing setup (#9396)

* fix(docs): update tanstack start routing setup

* Apply suggestion from @snowystinger

* fix spacing

* Apply suggestion from @snowystinger

* include in S2 router docs

---------

Co-authored-by: Robert Snow <snowystinger@gmail.com>
Co-authored-by: Robert Snow <rsnow@adobe.com>
Co-authored-by: Reid Barber <reid@reidbarber.com>

Author: 3 people

packages/dev/s2-docs/src/routers-s2.mdx

@@ -64,8 +64,14 @@ import {Step, Counter} from './Step';
         <Provider
           background="base"
           router={{
-            navigate: (href, opts) => router.navigate({...href, ...opts}),
-            useHref: href => router.buildLocation(href).href
+            navigate: (href, opts) => {
+              if (typeof href === "string") return;
+              return router.navigate({ ...href, ...opts });
+            },
+            useHref: (href) => {
+              if (typeof href === "string") return href;
+              return router.buildLocation(href).href;
+            }
           }}>
           {/*- end highlight -*/}
           {/* Your app here... */}

packages/dev/s2-docs/src/routers.mdx

@@ -1,7 +1,7 @@
 import {Counter} from './Step';
 
 <Counter />Render a `RouterProvider` at the root of your app to enable React Aria links to use your client side router. This accepts two props:
-        
+
 1. `navigate` – a function received from your router for performing a client side navigation programmatically.
 2. `useHref` (optional) – converts a router-specific href to a native HTML href, e.g. prepending a base path.
 
@@ -58,9 +58,15 @@ export const Route = createRootRoute({
     let router = useRouter();
     return (
       /*- begin highlight -*/
-      <RouterProvider 
-        navigate={(href, opts) => router.navigate({...href, ...opts})}
-        useHref={href => router.buildLocation(href).href}>
+      <RouterProvider
+        navigate={(href, opts) => {
+          if (typeof href === "string") return;
+          return router.navigate({ ...href, ...opts });
+        }}
+        useHref={(href) => {
+          if (typeof href === "string") return href;
+          return router.buildLocation(href).href;
+        }}>
         {/*- end highlight -*/}
         {/* Your app here... */}
       </RouterProvider>