docs: add warning about redirect check (#20680)

docs/2.guide/2.directory-structure/1.middleware.md

@@ -30,6 +30,9 @@ export default defineNuxtRouteMiddleware((to, from) => {
   if (to.params.id === '1') {
     return abortNavigation()
   }
+  // In a real app you would probably not redirect every route to `/`
+  // however it is important to check `to.path` before redirecting or you
+  // might get an infinite redirect loop
   if (to.path !== '/') {
     return navigateTo('/')
   }

docs/3.api/3.utils/abort-navigation.md

@@ -48,7 +48,7 @@ You can pass the error as a string:
 
 ```ts [middleware/auth.ts]
 export default defineNuxtRouteMiddleware((to, from) => {
-  const auth = useState('auth')
+  const user = useState('user')
 
   if (!user.value.isAuthorized) {
     return abortNavigation('Insufficient permissions.')