[Typo]: Remove from menu for non-existent pages

[yunrap]

trafficstars

Summary

I clicked on the menu because I was curious about the router, but the page was not provided.

Page

https://18.react.dev/learn/creating-a-react-app#react-router-v7

Details

I clicked on the menu because I was curious about the router, but the page was not provided.

If it's a non-existent page, I think it would be better if it wasn't shown at all in the menu.

I think it's a problem when I choose version 18, but not in version 19. https://react.dev/learn/creating-a-react-app#react-router-v7