Update README with links to documentation (#172)

* Update README with links to documentation

Add Features section and links to nodeadm, etcdadm repos.


* Apply suggestions from code review

Co-Authored-By: sarun87 <sarun87@gmail.com>

README.md

@@ -1,6 +1,17 @@
 # cctl
 
-CLI tool for Kubernetes cluster management. This tool lets you create, scale, backup and restore your air-gapped, on-premise Kubernetes cluster.
+cctl is a cluster lifecycle management tool that adopts the Kubernetes community's Cluster API and uses nodeadm and etcdadm to easily deploy and maintain highly-available Kubernetes clusters in on-premises, even air-gapped environments.  
+
+Along with [etcdadm](https://github.com/kubernetes-sigs/etcdadm) and [nodeadm](https://github.com/platform9/nodeadm), this tool makes up _klusterkit_, which lets you create, scale, backup and restore your air-gapped, on-premise Kubernetes cluster.
+
+## Features
+* Highly-available Kubernetes control plane and etcd
+* Deploy & manage secure etcd clusters
+* Works in air-gapped environments
+* Rolling upgrade support with rollback capability
+* Flannel (vxlan) CNI backend with plans to support other CNI backends
+* Backup & recovery of etcd clusters from quorum loss
+* Control plane protection from low memory/cpu situations
 
 ## Installation
 ```
@@ -30,6 +41,8 @@ $GOPATH/bin/cctl [command]
 
 ## Getting Started 
 
+If your setup has internet connectivity, follow these steps. For an airgapped environment, please see documentation [wiki](https://github.com/platform9/cctl/wiki).
+
 Ensure the correct version of the `nodeadm` and `etcdadm` binaries are placed in the `/opt/bin` directory of all nodes that will make up your cluster. 
 
 First, create the credentials used for the cluster.
@@ -47,3 +60,5 @@ Finally, create the first machine in your cluster.
 $GOPATH/bin/cctl create machine --ip $MACHINE_IP --role master
 ```
 
+
+#### For detailed documentation see [wiki](https://github.com/platform9/cctl/wiki)