Add dockerlings (#1208)

Author: furkan

README.md

@@ -104,6 +104,7 @@ _Source:_ [What is Docker](https://www.docker.com/why-docker/)
 -   [Docker katas](https://github.com/eficode-academy/docker-katas) A series of labs that will take you from "Hello Docker" to deploying a containerized web application to a server.
 -   [Docker simplified in 55 seconds](https://www.youtube.com/watch?v=vP_4DlOH1G4): An animated high-level introduction to Docker. Think of it as a visual tl;dr that makes it easier to dive into more complex learning materials.
 -   [Docker Training](https://training.mirantis.com) :heavy_dollar_sign:
+-   [Dockerlings](https://github.com/furkan/dockerlings): Learn docker from inside your terminal, with a modern TUI and bite sized exercises (by [furkan](https://github.com/furkan))
 
 -   [Introduction à Docker](https://blog.stephane-robert.info/docs/conteneurs/moteurs-conteneurs/docker/) A dedicated section to master Docker on a French site about DevSecOps: From the basics to best practices, including optimizing, securing your containers... 
 -   [Learn Docker](https://github.com/dwyl/learn-docker): step-by-step tutorial and more resources (video, articles, cheat sheets) by [@dwyl](https://github.com/dwyl)