content type Argument shows up on "create content" page

Issue Summary

Hi. Great module. I have used it today and I did find one bug.

When going to;
/node/add

"Argument" turns up, but pressing it will give you a access denied message.

Maybe it would be better if it did not show up on the "create content" page since it is not a independent piece of content.

It is possible to remove the item from the menu, but it still shows up on the "create content" page.