chore(docs): refactor the charts, rbac & engine manifests (#324)

Signed-off-by: shubhamchaudhary <shubham.chaudhary@mayadata.io>

charts/generic/node-drain/engine.yaml

@@ -23,6 +23,7 @@ spec:
       spec:
         components:
           nodeSelector: 
+            # provide the node labels
             kubernetes.io/hostname: 'node02'        
           env:
             # set node name

charts/generic/node-drain/experiment.yaml

@@ -48,9 +48,6 @@ spec:
     command:
     - /bin/bash
     env:
-   
-    - name: LIVENESS_APP_LABEL
-      value: ''
     
     - name: APP_NODE
       value: ''
@@ -67,8 +64,5 @@ spec:
     - name: RAMP_TIME
       value: ''
 
-    - name: LIVENESS_APP_NAMESPACE
-      value: '' 
-
     labels:
       name: node-drain