Currently in MongoDB if a customer has not explicitly set a value for a configurable option it's possible that they are unable to view the cluster's (MongoDB's) default value. 

For example when a customer is attempting to find the cluster maxChunkSize setting and runs the following commands via mongosh and the customer has not explicitly set a default maxChunkSize for the cluster the findOne query will return null as shown in the attached image. 

Requested Improvement:

Provide a method to display the cluster's default values for sharding options so that customers do not have to find the default value for the given option in the documentation.