docs: add server routes documentation

docs/content/2.guide/2.features/9.api-routes.md

@@ -1,7 +1,106 @@
 # API Routes
 
-::NeedContribution
-::
+Nuxt will automatically register files in the `/server/api` directory to create API endpoints.
 
-::ReadMore{link="/guide/directory-structure/server"}
-::
+To handle requests, each file can export a default function or an instance of a [h3 app](https://github.com/unjs/h3#usage) to add even more functionality to an API route. These can directly return a promise, JSON data or simply use `res.end()`.
+
+Learn more about [h3 methods](https://www.jsdocs.io/package/h3#package-index-functions).
+
+## Route Parameter
+
+For ease of use, routes that are dependent on a parameter can specify the parameter within brackets in the file name `/api/hello/[parameter].ts`.
+
+```ts [/server/api/hello/[name].ts]
+export default eventHandler(event => {
+    return `Hello, ${event.context.params.name}!`
+})
+```
+
+## Method Matching
+
+Routes can be suffixed with `.get`, `.post`, `.put`, `.delete` to match a [supported HTTP Method](https://github.com/unjs/nitro/blob/main/src/runtime/virtual/server-handlers.d.ts#L7).
+
+```ts [/server/api/test.post.ts]
+export default eventHandler(() => 'Test post handler')
+```
+
+Given the example above, the `test` route will be declared as a `POST` route.
+
+## Catch All Route
+
+A catch all route can be defined by creating a file in the `api` directory with the name `[...].ts`. This route will be triggered for all requests that do not match any other route.
+
+This is useful for special use cases as well as fallback error handling.
+
+```ts [/server/api/[...].ts]
+export default eventHandler(event => `Default page`)
+```
+
+## Examples
+
+### Hello World
+
+```ts [/server/api/hello.ts]
+export default eventHandler(() => '<h1>Hello World</h1>')
+```
+
+### POST Request
+
+<code-group>
+<code-block label="Basic" active>
+
+```ts [/server/api/hello.ts]
+export default eventHandler(async (event) => {
+    const body = await useBody(event.req); // only for POST | PUT | PATCH | DELETE requests
+
+    return { body }
+})
+```
+
+</code-block>
+<code-block label="Method Matching">
+
+```ts [/server/api/hello.post.ts]
+export default defineEventHandler(() => '<h1>Hello World</h1>')
+```
+
+</code-block>
+</code-group>
+
+### Using Router 
+
+```ts [/server/api/hello.ts]
+import { createApp, createRouter } from 'h3'
+
+const app = createApp()
+const router = createRouter()
+
+app.use(router)
+
+router.get('/', () => 'Hello World')
+
+export default app
+```
+
+### Using Node.js style
+
+```ts [server/api/node.ts]
+import type { IncomingMessage, ServerResponse } from 'http'
+
+export default async (req: IncomingMessage, res: ServerResponse) => {
+  res.statusCode = 200
+  res.end('Works!')
+}
+```
+
+### Access Request Data
+
+```ts
+export default eventHandler(async (event) => {
+  const params = event.context.params;
+  const body = await useBody(event.req);  // only for POST | PUT | PATCH | DELETE requests
+  const cookies = useCookies(event.req);
+
+  return { params, body, cookies };
+});
+```