docs(server): add nitro config and storage examples (#6507)

Co-authored-by: Pooya Parsa <pooya@pi0.io>

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

@@ -162,6 +162,23 @@ export default defineEventHandler((event) => {
 
 ## Advanced Usage Examples
 
+### Nitro Configuration
+
+You can use `nitro` key in `nuxt.config` to directly set [Nitro Configuration](https://nitro.unjs.io/config/).
+
+::alert{type=warning}
+This is an advanced option. Custom config can affect production deployments and we upgrade Nitro in semver-minor versions of Nuxt 3. meaning, configuration interface might be changed over the time.
+::
+
+```ts [nuxt.config.ts]
+import { defineNuxtConfig } from 'nuxt'
+
+export default defineNuxtConfig({
+  // https://nitro.unjs.io/config
+  nitro: {}
+})
+```
+
 ### Using a Nested Router
 
 ```ts [/server/api/hello.ts]
@@ -209,3 +226,67 @@ export default (req, res, next) => {
 ::alert{type=warning}
 Never combine `next()` callback with a legacy middleware that is `async` or returns a `Promise`!
 ::
+
+### Server Storage
+
+Nitro Provides a cross platform [Stroage Layer](https://nitro.unjs.io/guide/storage.html). In oder to configure additional storage mountpoints, you can use `nitro.storage`.
+
+#### Example: Using Redis
+
+```ts [nuxt.config.ts]
+import { defineNuxtConfig } from 'nuxt'
+
+export default defineNuxtConfig({
+  nitro: {
+    storage: {
+      'redis': {
+        driver: 'redis',
+        /* redis connector options */
+        port: 6379, // Redis port
+        host: "127.0.0.1", // Redis host
+        username: "", // needs Redis >= 6
+        password: "",
+        db: 0, // Defaults to 0
+      },
+    }
+  }
+})
+```
+
+Create a new file in `server/api/test.post.ts`:
+
+```ts [/server/api/test.post.ts]
+export default defineEventHandler(async event => {
+  const body = await useBody(event)
+  await useStorage().setItem('redis:test', body)
+  return 'Data is set'
+})
+```
+
+Create a new file in `server/api/test.get.ts`:
+
+```ts [/server/api/test.get.ts]
+export default async defineEventHandler(event => {
+  const data = await useStorage().getItem('redis:test')
+  return data
+})
+```
+
+Create a new file in `app.vue`:
+
+```vue [app.vue]
+<template>
+  <div>
+    <div>Post state: {{ resDataSuccess }}</div>
+    <div>Get Data: {{ resData.text }}</div>
+  </div>
+</template>
+
+<script setup lang="ts">
+  const { data: resDataSuccess } = await useFetch('/api/test', {
+      method: 'post',
+      body: { text: 'Nuxt is Awesome!' }
+  })
+  const { data: resData } = await useFetch('/api/test')
+</script>
+```