doc: remove outdated elixir wrapper

readme.md

@@ -43,7 +43,6 @@ A REST API service is available as well
 | TypeScript | [jikants](https://github.com/Julien-Broyard/jikants) by Julien Broyard<br>[jikan-client](https://github.com/javi11/jikan-client) by Javier Blanco |
 | PHP        | [jikan-php](https://github.com/janvernieuwe/jikan-jikanPHP) by Jan Vernieuwe |
 | .NET       | [Jikan.net](https://github.com/Ervie/jikan.net) by Ervie |
-| Elixir     | [JikanEx](https://github.com/seanbreckenridge/jikan_ex) by Sean Breckenridge |
 | Go         | [jikan-go](https://github.com/darenliang/jikan-go) by Daren Liang<br>[jikan2go](https://github.com/nokusukun/jikan2go) by nokusukun |
 | Ruby       | [Jikan.rb](https://github.com/Zerocchi/jikan.rb) by Zerocchi |
 | Dart       | [jikan-dart](https://github.com/charafau/jikan-dart) by Rafal Wachol |