Merge pull request #426 from KhiopsML/port-420-document-sklearn-helpers

Expose the sklearn.helpers package in the API docs (porting from v10 to v11)

Author: tramora

doc/sklearn/index.rst

@@ -15,6 +15,7 @@ khiops.sklearn
   :nosignatures:
 
   estimators
+  helpers
 
 Related Docs
 ------------