feat: add new tutorial with Gatsby

Closes #310.

Author: e0ipso

modules/recipes_magazin/default_content/images/with-gatsby.png

@@ -46,3 +46,4 @@ Contenta Docker: Adding a Consumer, "Building off of the Contenta Docker project
 Contenta Docker: GraphQL and Apollo, "In addition to REST, Contenta includes an instance of GraphQL. In this screencast, we'll use the apollo-client web component to pull data into our Polymer frontend application.",default-article.png,https://www.youtube.com/watch?v=DqySMqvJ5ro,Watch Video,GraphQL,heymp
 How to install Contenta headless Drupal on a Digital Ocean droplet, "Installing it is generally a straightforward process, but the documentation does assume a level of Drupal knowledge that I don’t possess.",default-article.png,https://mk.gg/contenta-drupal-on-digital-ocean/,Read Article,Miscelaneous,Matt Kane
 JSON-RPC to decouple everything else, "During the week of DrupalCon we discussed some limitations decoupling Drupal. We concluded that we need a reliable, flexible and secure way for Drupal developers to decouple everything else.",johnson-wang-515951-unsplash.jpg,https://www.lullabot.com/articles/jsonrpc-to-decouple-everything-else,Read Article,Miscelaneous,Mateu Aguiló Bosch
+Gatsby JS: A Powerful Front End Tool for Decoupled Devs, "Want to learn about GatsbyJS? What is it? How can it help you and your team? Is it a framework? Is it a static site generator? GatsbyJS is an exciting way of thinking about building sites for the modern web.",with-gatsby.png,https://www.youtube.com/watch?v=UgWBJnbZ9jU,Watch Video,Miscelaneous,Grayson Hicks