[docs] add docs for sequence (#2317)

documentation/docs/04-hooks.md

@@ -79,6 +79,8 @@ export async function handle({ request, resolve }) {
 }
 ```
 
+You can add call multiple `handle` functions with [the `sequence` helper function](#modules-@sveltejs/kit/hooks).
+
 ### handleError
 
 If an error is thrown during rendering, this function will be called with the `error` and the `request` that caused it. This allows you to send data to an error tracking service, or to customise the formatting before printing the error to the console.

documentation/docs/05-modules.md

@@ -75,3 +75,22 @@ import { build, files, timestamp } from '$service-worker';
 - `build` is an array of URL strings representing the files generated by Vite, suitable for caching with `cache.addAll(build)`
 - `files` is an array of URL strings representing the files in your `static` directory, or whatever directory is specified by [`config.kit.files.assets`](#configuration). You can exclude certain files from `static` directory using [`config.kit.serviceWorker.exclude`](#configuration)
 - `timestamp` is the result of calling `Date.now()` at build time. It's useful for generating unique cache names inside your service worker, so that a later deployment of your app can invalidate old caches
+
+### @sveltejs/kit/hooks
+
+This modules provides a helper function to sequence multiple `handle` calls.
+
+```js
+import { sequence } from '@sveltejs/kit/hooks';
+
+async function first({ request, resolve }) {
+  console.log('first');
+  return await resolve(request);
+}
+async function second({ request, resolve }) {
+  console.log('second');
+  return await resolve(request);
+}
+
+export const handle = sequence(first, second);
+```