The article refers to the unclassified memos that Comey wrote himself about his conversations with the President. No matter what you believe about the deliberate release of these to the public, don't imply it is more than it is.
Don't know the specifics.. however, Comey had no business removing anything. Even his own memos are the property of the United States.
There is more to this. After being fired, Comey handed over a big fat package of documents related to Trump to Herr Mueller. It was illegal for him to do that. Those were not his documents to give.. he stole them.
I actually find this witch hunt amusing. A witch hunt that goes nowhere winds up making fools of those perpetrating it.