Default "Ready?" checkbox in Teams tab to unchecked

Prior to pulling a story into an iteration, during the backlog grooming session, we go through stories and check the ready checkmark to ensure they are ready to be worked in the iteration. We don't need the checkmark checked when the story is entered because the team has not yet vetted the story to ensure completeness; however, it defaults to checked now so it's an extra step for our team members to uncheck it every time.