Broken link to kafka recipe in the docs

<img width="341" alt="Screenshot 2020-10-11 at 13 40 28" src="https://user-images.githubusercontent.com/377206/95677677-67096b00-0bc7-11eb-8983-d1f5bcac87b1.png">

`A running kafka instance` link on this page https://tv.kitchen/docs/recipes/extracting-captions is broken.