refactor: move routes in dedicated files + improve routes management

start/routes/favicon.ts

@@ -0,0 +1,9 @@
+import router from '@adonisjs/core/services/router';
+const FaviconsController = () => import('#controllers/favicons_controller');
+
+/**
+ * Favicon routes
+ */
+router.group(() => {
+  router.get('/favicon', [FaviconsController, 'index']).as('favicon');
+});