docs: show a redirect function in the route metadata guide

The redirect routes section only showed string targets.

Author: byrondover

apps/docs-analog/src/content/features/routing/metadata.md

@@ -74,6 +74,15 @@ Nested redirects always require an absolute path.
 
 :::
 
+`redirectTo` also accepts Angular's `RedirectFunction`, which receives the matched route's params, query params and data, can use `inject()`, and returns the target path or a `UrlTree`:
+
+```ts
+export const routeMeta: RouteMeta = {
+  redirectTo: ({ params }) => `/cities/${params['cityId']}`,
+  pathMatch: 'full',
+};
+```
+
 ## Route Meta Tags
 
 The `RouteMeta` type has a property `meta` which can be used to define a list of meta tags for each route: