docs: add local modules ordering

docs/2.guide/2.directory-structure/1.modules.md

@@ -47,6 +47,15 @@ export default defineEventHandler(() => {
 
 When starting Nuxt, the `hello` module will be registered and the `/api/hello` route will be available.
 
+The local modules are registered by alphabetical order. You can change the order by prefixing with a number if front of each directory:
+
+`ˋ`md
+modules/
+  1.first-module/
+    index.ts
+  2.second-module.ts
+ˋ`ˋ
+
 :ReadMore{link="/docs/guide/going-further/modules"}
 
 ::