[ci skip] Added +object+ and +attributes+ to create! description for rdoc

Added missing +object+ and +attributes+ so that `create!` is not flagged by rdoc.
Yes, Base#create will return the object even if validations fail. In the sentence I already say 'Works like Base#create except that it raises a RecordInvalid error' which implied that the behavior is unlike Base#create. Do you think I still need to add 'unlike Base#create'?

Or are you saying that I should change it to 'Raises a RecordInvalid error if validations fail, unlike Base#create'?.