Wrong field in samples section of data-connect-dataset-groupmembers.md documentation

[pxmonti]

Describe the bug
The samples section of the documentation uses a field that is not in the specifications. The wrong field is "puser", the correct field should be "ObjectId"

To Reproduce
Just browse the documentation page and look at the "Sample" section.
data-connect-dataset-groupmembers.md

Expected behavior
Please, update the documentation section and replace puser with ObjectId.