New GraphQL.js redirects do not work internally, and some links are broken

まだ誰も着手していません。

### Description

GraphQL.js webpages are still included in the website, and are still searchable and navigable. However, when you reload the page you are sent to GraphQL-js.org and the webpage doesn't necessarily exist.

### Steps to Reproduce

1. Visit https://graphql.org/
2. Enter "Running an Express GraphQL Server" into the search bar and press the top link
3. Notice that you have been directed to `https://graphql.org/graphql-js/running-an-express-graphql-server/` and a web page is rendered
4. Reload the page (or visit `https://graphql.org/graphql-js/running-an-express-graphql-server/` directly)
5. Notice that you have been redirected to `https://www.graphql-js.org/running-an-express-graphql-server/` and greeted with a 404.

### Expected Result

In step 3 you should be directed to graphql-js.org (or the search result should not appear in the first place?)

If you visit `https://graphql.org/graphql-js/running-an-express-graphql-server/` directly, you should be redirected to an extant page on `graphql-js.org`

### Actual Result

Old content rendered in step 3.

404 rendered in step 5.

issue に記載されている graphql.org のホームページ、検索結果、直接 URL を使ってリダイレクトを再現します。/graphql-js/running-an-express-graphql-server/ パスに対する Web サイトのルーティングと検索処理を追跡します。完了の条件は、古いページが提供されなくなり、直接アクセスが既存の graphql-js.org ページに解決されることです。

索引モデルが issue の本文から書いたものです。