docs: Clarify Vercel Api route mappings

docs/content/1.guide/3.routing.md

@@ -13,10 +13,6 @@ Nitro supports file-based routing for your API routes.
 
 Handler files inside `api/` and `routes/` directory will be automatically mapped to [unjs/h3](https://github.com/unjs/h3) routes.
 
-::alert{type=primary}
-Due to some providers like Vercel using  top-level `api/` directory as a feature, Nitro also supports `routes/api/` to create API routes.
-::
-
 ```md
 api/
   test.ts      <-- /api/test
@@ -25,6 +21,13 @@ routes/
 nitro.config.ts
 ```
 
+::alert{type=primary}
+Some providers like Vercel use a top-level `api/` directory as a feature. This
+means that routes placed in `/api` wont work. Since Nitro also supports
+`routes/api/` to create API routes, simple move your api folder to the
+`routes/` folder.
+::
+
 ::alert
 If you are using [Nuxt](https://nuxt.com), move the `api/` and `routes/` inside the `server/` directory.
 ::