update: sorting navigation page

docs/en/framework/ui/angular/sorting-navigation-elements.md

@@ -19,19 +19,18 @@ This documentation describes how the navigation elements are sorted and how to c
 
 # How to Customize
 
-**`in app.module.ts`**
+**`in app.config.ts`**
 
 ```ts
 import { SORT_COMPARE_FUNC } from "@abp/ng.core";
 
-@NgModule({
+export const appConfig: ApplicationConfig = {
   providers: [
-    ...{
+    // ...
+    {
       provide: SORT_COMPARE_FUNC,
       useFactory: yourCompareFuncFactory,
     },
   ],
-  // imports, declarations, and bootstrap
-})
-export class AppModule {}
+};
 ```