Fix ref to what-is-kubernetes

Author: Rishit-dagli

content/en/_index.html

@@ -8,7 +8,7 @@
 
 {{< blocks/section id="oceanNodes" >}}
 {{% blocks/feature image="flower" %}}
-[Kubernetes]({{< relref "/docs/concepts/overview/what-is-kubernetes" >}}), also known as K8s, is an open-source system for automating deployment, scaling, and management of containerized applications.
+[Kubernetes]({{< relref "/docs/concepts/overview/" >}}), also known as K8s, is an open-source system for automating deployment, scaling, and management of containerized applications.
 
 It groups containers that make up an application into logical units for easy management and discovery. Kubernetes builds upon [15 years of experience of running production workloads at Google](http://queue.acm.org/detail.cfm?id=2898444), combined with best-of-breed ideas and practices from the community.
 {{% /blocks/feature %}}