[DOC]: Verify docs in DGL code under the cugraph/python/cugraph/cugraph/gnn/dgl_extensions/

[BradReesWork]

How would you describe the priority of this documentation request

Critical (currently preventing usage)

Please provide a link or source to the relevant docs

cugraph/python/cugraph/cugraph/gnn/dgl_extensions/

Describe the problems in the documentation

verify and fix any missing docs

(Optional) Propose a correction

No response

Code of Conduct

• [X] I agree to follow cuGraph's Code of Conduct
• [X] I have searched the open documentation issues and have found no duplicates for this bug report