docs: added addServerHandler example to modules author guide (#22603)

docs/2.guide/3.going-further/3.modules.md

@@ -375,6 +375,40 @@ export default defineNuxtModule({
 })
 ```
 
+#### Injecting Server Routes With `addServerHandler`
+
+```ts
+import { defineNuxtModule, addServerHandler, createResolver } from '@nuxt/kit'
+
+export default defineNuxtModule({
+  setup(options, nuxt) {
+    const resolver = createResolver(import.meta.url)
+
+    addServerHandler({
+      route: '/api/hello',
+      handler: resolver.resolve('./runtime/server/api/hello/index.get.ts')
+    })
+  }
+})
+```
+
+You can also add a dynamic server route:
+
+```ts
+import { defineNuxtModule, addServerHandler, createResolver } from '@nuxt/kit'
+
+export default defineNuxtModule({
+  setup(options, nuxt) {
+    const resolver = createResolver(import.meta.url)
+
+    addServerHandler({
+      route: '/api/hello/:name',
+      handler: resolver.resolve('./runtime/server/api/hello/[name].get.ts')
+    })
+  }
+})
+```
+
 #### Injecting Other Assets
 
 If your module should provide other kinds of assets, they can also be injected. Here's a simple example module injecting a stylesheet through Nuxt's `css` array.