[docs] fix typo

Fixed "beend" to "been".

site/content/blog/2021-10-01-whats-new-in-svelte-october-2021.md

@@ -33,7 +33,7 @@ Notable SvelteKit improvements this month include...
 - Svelte libraries should now work out-of-the-box without any Vite configuration ([#2343](https://github.com/sveltejs/kit/pull/2343))
 - Improvements to package exports field ([#2345](https://github.com/sveltejs/kit/pull/2345) and [#2327](https://github.com/sveltejs/kit/pull/2327))
 - [breaking] The `prerender.pages` config option has been renamed to `prerender.entries` ([#2380](https://github.com/sveltejs/kit/pull/2380))
-- A new generic argument has beend added to allow typing Body from hooks ([#2413](https://github.com/sveltejs/kit/pull/2413))
+- A new generic argument has been added to allow typing Body from hooks ([#2413](https://github.com/sveltejs/kit/pull/2413))
 - The `svelte` field will be added to package.json when running the package command ([#2431](https://github.com/sveltejs/kit/pull/2431))
 - [breaking] The `context` parameter of the load function was renamed to `stuff` ([#2439](https://github.com/sveltejs/kit/pull/2439))
 - Added an `entryPoint` option for building a custom server with `adapter-node` ([#2414](https://github.com/sveltejs/kit/pull/2414))