add kubesphere icon animation and katacoda scenario

Signed-off-by: FeynmanZhou <pengfeizhou@yunify.com>

README.md

@@ -1,5 +1,5 @@
 <p align="center">
-<img src="docs/images/kubesphere-logo.png" alt="banner" width="200px">
+<a href="https://kubesphere.io/"><img src="docs/images/kubesphere-icon.gif" alt="banner" width="200px"></a>
 </p>
 
 <p align="center">
@@ -137,7 +137,10 @@ kubectl logs -n kubesphere-system $(kubectl get pod -n kubesphere-system -l app=
 
 > 👨‍💻 No Kubernetes cluster? Try [All-in-one](https://kubesphere.io/docs/quick-start/all-in-one-on-linux/) to install a single-node Kubernetes and KubeSphere on your Linux machine. 
 
-### KubeSphere for hosted Kubernetes services
+### 🐯 Katacoda for Quick Learning
+
+[Katacoda](https://www.katacoda.com/) allows you to explore how to install KubeSphere on an existing Kubernetes cluster in a browser. You can start the [Katacoda scenario with KubeSphere](https://www.katacoda.com/kubesphere/scenarios/install-kubesphere-on-kubernetes) in minutes.
+### KubeSphere for Hosted Kubernetes Services
 
 KubeSphere is hosted on the following cloud providers, you can try KubeSphere by one-click installation on their hosted Kubernetes services. 
 
@@ -160,7 +163,7 @@ We :heart: your contribution. The [community](https://github.com/kubesphere/comm
 
 Please submit any KubeSphere bugs, issues, and feature requests to [KubeSphere GitHub Issue](https://github.com/kubesphere/kubesphere/issues).
 
-## Who are using KubeSphere
+## Who are Using KubeSphere
 
 The [user case studies](https://kubesphere.io/case/) page includes the user list of the project. You can [leave a comment](https://github.com/kubesphere/kubesphere/issues/4123) to let us know your use case.