Newsletter 13: Add "Chargrid Roguelike Tutorial 2020" (#240)

* Add "Chargrid Roguelike Tutorial 2020" section for newsletter 13

* Remove unnecessary pair of brackets

Co-authored-by: Joe Clay <[email protected]>

* Newsletter 13: Chargrid Tut 2020: Style tweak

Co-authored-by: Joe Clay <[email protected]>
Co-authored-by: Andrey Lesnikóv <[email protected]>

Author: 3 people

content/posts/newsletter-013/chargrid-roguelike-tutorial-2020.png

@@ -102,6 +102,26 @@ work with graphics in Rust using [SDL2][sdl2] library.
 [@bugzmanov]: https://twitter.com/bugzmanov
 [sdl2]:https://www.libsdl.org/
 
+### [Chargrid Roguelike Tutorial 2020][chargrid-roguelike-tutorial-2020]
+
+![Chargrid Roguelike Tutorial 2020](chargrid-roguelike-tutorial-2020.png)
+
+[Chargrid][chargrid] by [@stevebob] is a collection of crates for building
+applications with text UIs that run in terminals, graphical windows, and web
+pages. It was made specifically with roguelike development in mind, though is
+general-purpose enough to be used for other applications.
+
+[Chargrid Roguelike Tutorial 2020][chargrid-roguelike-tutorial-2020]
+is a tutorial series about making a traditional roguelike from scratch
+using chargrid for rendering and input handling. Reference code is available in
+[this git repo][chargrid-roguelike-tutorial-2020-reference-code]
+organized with one branch for each subsection.
+
+[chargrid-roguelike-tutorial-2020]: https://gridbugs.org/roguelike-tutorial-2020/
+[chargrid-roguelike-tutorial-2020-reference-code]: https://github.com/stevebob/chargrid-roguelike-tutorial-2020
+[chargrid]: https://github.com/stevebob/chargrid/
+[@stevebob]: https://github.com/stevebob
+
 ## Library & Tooling Updates
 
 ### [hexasphere] v1.0