Documentation of fieldName and add encoding to Values.yaml for CRD Secret String instantiation

[bigbosst]

Is your feature request related to a problem? Please describe. Using the annotation you only need to provide the user and secret name. However the CR requires 'fields' to be added. one of these fields is 'encoding' However, this does not seem to be a field we can set in the values.yaml. I was also unsure what 'fieldName' was used for looking at the existing documentation.

Describe the solution you'd like Better documentation for the use of "fieldName", possibly using the 'password' value to match the annotation example in the readme.

Setting the default operator deployment values for encryption, similar to length

Describe alternatives you've considered Leave it as is and still document 'fieldName'