[FLINK-30280] Document logging configuration behaviour

Author: mxm

helm/flink-kubernetes-operator/values.yaml

@@ -122,8 +122,14 @@ webhook:
   #   key: password-key
 
 defaultConfiguration:
+  # If set to true, creates ConfigMaps/VolumeMounts. If set to false, no configuration will be created.
+  # All below fields will be ignored if create is set to false.
   create: true
-  # Set append to false to replace configuration files
+  # If set to true,
+  #      (1) loads the built-in default configuration
+  #      (2) appends the below flink-conf and logging configuration overrides
+  # If set to false, loads just the overrides as in (2).
+  # This option has not effect, if create is equal to false.
   append: true
   flink-conf.yaml: |+
     # Flink Config Overrides