Don't break the back button when redirecting legacy routes (#4305)

* Don't break the back button when redirecting legacy routes

* Prettier

frontend/lib/redirect-legacy-routes.ts

@@ -4,8 +4,12 @@ export default function redirectLegacyRoutes() {
   const { hash } = window.location
   if (hash && hash.startsWith('#/examples/')) {
     const category = hash.replace('#/examples/', '')
-    navigate(`category/${category}`)
+    navigate(`category/${category}`, {
+      replace: true,
+    })
   } else if (hash === '#/endpoint') {
-    navigate('endpoint')
+    navigate('endpoint', {
+      replace: true,
+    })
   }
 }