Added title to helm installation steps(Cluster Mode)

Signed-off-by: Gbadebo Bello <gbahdeybohbello@gmail.com>

Author: Gbahdeyboh

website/docs/litmus-installation-cluster.md

@@ -23,7 +23,7 @@ Installation of Litmus can be done using either of the below methods
 - [Helm3](#helm_install) chart or
 - [Kubectl](#kubectl_install) yaml spec file
 
-### Installation Steps
+### Install Litmus using Helm
 
 The helm chart will install all the required service account configuration and chaos control plane.