Update contribution.md as completion article

Since the page isn't really asking for contributors any longer I wanna pivot and turn it into a page that marks the tutorial as completed and points out similar tutorials/examples.

book/src/pong-tutorial/contribution.md

@@ -1,9 +1,28 @@
-# Call for contribution
+# Tutorial completed!
 
 And... that's where the pong chapter ends. We hope you found it useful!
 
 You can find the entire code with balls, score and music on the example pages available [here](https://github.com/amethyst/amethyst/tree/master/examples/pong).
 
-For more examples from the community you can check out this list of [Games made with Amethyst](https://community.amethyst.rs/t/games-made-with-amethyst/134). You can get additional help by leaving a post on [our forum](https://community.amethyst.rs) or on our [Discord server](https://discord.gg/amethyst).
+Next up in this book we will explain how Amethyst does Math, Input, Assets and so on. Whenever you have a need for more learning-by-example materials just come back to this page for an overview of available resources.
+
+## Other tutorials or examples
+
+[Amethyst Quickstarter](https://github.com/amethyst/amethyst-starter-2d)
+Seed project for 2D games. This project template will get you from 0 to drawing something on the screen in no time.
+
+Showcase Game: [Evoli](https://github.com/amethyst/evoli)
+An ecosystem-simulation game, 3D
+
+Showcase Game: [Space Menace](https://github.com/amethyst/space-menace/)
+An action 2D platformer
+
+Showcase Game: [Survivor](https://github.com/jaynus/survival) (unannounced, 2D)
+
+For more examples from the community you can check out this list of [Games made with Amethyst](https://community.amethyst.rs/t/games-made-with-amethyst/134).
+
+## Come talk to us
+
+You can get additional help by leaving a post on [our forum](https://community.amethyst.rs) or on our [Discord server](https://discord.gg/amethyst). We'd also love to hear your ideas for other tutorials we should consider adding to this book.
 
 If you want to extend this tutorial (e.g., add a main menu, add pause/resume functionality, etc.), feel free to ping us on Discord or in a GitHub issue!