Website: fix index name in search (#1634)

While id and api key are fine now, the index name changed too and this
should be fixed by this PR now.

If this works, after merging this we should also bump the `release`
branch

Author: ch1bo

docs/docusaurus.config.js

@@ -276,7 +276,7 @@ const config = {
       algolia: {
         appId: "OF3CR7K89X",
         apiKey: "09b2fc0200d06fb433a5f4ced7c9d427",
-        indexName: "hydra-family",
+        indexName: "hydra",
         searchPagePath: "search",
         contextualSearch: true,
       },