add resources: hands-on tutorials and meshery playground (#981)

* add Meshery playground to interactive-environments

* add tutorials

Author: vishalvivekm

docs/learning-resources/courses.md

@@ -16,3 +16,4 @@ MOOC Courses / Tutorials
   - [Kubernetes Tutorial by Tutorialspoint](http://www.tutorialspoint.com/kubernetes/)
   - [Imperative vs. Declarative — a Kubernetes Tutorial](https://medium.com/payscale-tech/imperative-vs-declarative-a-kubernetes-tutorial-4be66c5d8914) by [Adrien Trouillaud](https://github.com/adrienjt/)
   - [Learning Kubernetes, The Chinese Taoist Way](https://github.com/caicloud/kube-ladder)
+  - [Hands-on tutorials on cloud and cloud native technologies](https://docs.meshery.io/guides/tutorials)

docs/learning-resources/interactive-environments.md

@@ -7,3 +7,4 @@ Interactive Learning Environments
 * [Kubernetes Bootcamp](http://kubernetesbootcamp.github.io/kubernetes-bootcamp/)
 * [Play with Kubernetes](http://labs.play-with-k8s.com/)
 * [Kubernetes Labs for practice](https://www.sharelearn.net/practice/k8slabs/)
+* [Meshery Playground](https://play.meshery.io/)