docs: note that middleware runs on error pages as well

resolves #23477

Author: danielroe

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

@@ -134,6 +134,8 @@ export default defineNuxtRouteMiddleware(to => {
 })
 ```
 
+This is true even if you throw an error in your middleware on the server, and an error page is rendered. The middleware will still run again in the browser.
+
 ::note
 Rendering an error page is an entirely separate page load, meaning any registered middleware will run again. You can use [`useError`](/docs/getting-started/error-handling#useerror) in middleware to check if an error is being handled.
 ::