Fix apply link

The apply link on the what-is-docsearch page resolves to the non-existent https://docsearch.algolia.com/docs/apply URL where it should point to https://docsearch.algolia.com/apply.

Author: lupinitylabs

packages/website/docs/what-is-docsearch.md

@@ -26,7 +26,7 @@ You can now [apply to the program][3]
 
 [1]: https://opencollective.com/algolia
 [2]: who-can-apply
-[3]: apply
+[3]: /apply
 [4]: https://www.algolia.com/products/search-and-discovery/crawler/
 [5]: https://crawler.algolia.com/
 [6]: https://www.algolia.com/doc/ui-libraries/autocomplete/introduction/what-is-autocomplete/