Add namespace parameter to chart values

closes #189

charts/helm-dashboard/templates/deployment.yaml

@@ -42,6 +42,10 @@ spec:
               value: /opt/dashboard/helm/data
             - name: DEBUG
               value: {{- ternary " 1" "" .Values.debug }}
+            {{- if .Values.dashboard.namespace }}
+            - name: HELM_NAMESPACE
+              value: {{ .Values.dashboard.namespace }}
+            {{end}}
           ports:
             - name: http
               containerPort: 8080

charts/helm-dashboard/values.yaml

@@ -30,6 +30,10 @@ resources:
 
 dashboard:
   allowWriteActions: true
+
+  # default namespace for Helm operations
+  namespace: ""
+
   persistence:
     enabled: true