Add strimzi minimal configs for helm

Resolves #357 (closed)

Adds minimal configuration options for helm minimal installation variant

helm/preconfigs/minimal.yaml

-cp-helm-charts:
-  cp-zookeeper:
-    servers: 1
-
-  cp-kafka:
-    brokers: 1
-    configurationOverrides:
-      offsets.topic.replication.factor: "1"
-
 operator:
   sloChecker:
     droppedRecordsKStreams:
       enabled: false
   resultsVolume:
     enabled: false
+
+strimzi:
+  kafka:
+    replicas: 1
+    config: 
+      "offsets.topic.replication.factor": "1"
+  zookeeper:
+    replicas: 1
+  
\ No newline at end of file