mention registration of upgrading menu

Author: its-miroma

develop/custom-recipe-types.md

@@ -90,6 +90,10 @@ To detect when the user takes the result out, we create an anonymous subclass of
 
 To prevent deleting items, it is important to drop the inputs back when the screen is closed, as shown in the `removed` method.
 
+You also need to add the menu to the registry:
+
+<<< @/reference/latest/src/main/java/com/example/docs/recipe/ExampleModRecipes.java#upgrading-menu-registration
+
 ## Recipe Synchronization {#recipe-synchronization}
 
 ::: info

reference/latest/src/main/java/com/example/docs/recipe/ExampleModRecipes.java

@@ -42,7 +42,7 @@ public class ExampleModRecipes implements ModInitializer {
 					new RecipeBookCategory()
 	);
 
-	//:::menuRegistration
+	// #region upgrading-menu-registration
 	public static final MenuType<UpgradingMenu> UPGRADING_MENU_TYPE = Registry.register(
 					BuiltInRegistries.MENU,
 					Identifier.fromNamespaceAndPath(ExampleMod.MOD_ID, "upgrading"),
@@ -58,7 +58,7 @@ public class ExampleModRecipes implements ModInitializer {
 									.setId(ResourceKey.create(Registries.BLOCK, UPGRADING_BLOCK_ID))
 					)
 	);
-	//:::menuRegistration
+	// #endregion upgrading-menu-registration
 
 	@Override
 	public void onInitialize() {