is going to focus on one of the toughest decisions the Kardashian-Jenner family has ever made: ending their E! reality show after 20 seasons.«We all have to be on the same page, because it's a huge decision,» Kris Jenner tells her family in Thursday's preview clip, before they're seen making the tearful announcement to the members of their TV crew.«It was just the hardest conversation that we've ever had to have,» Kim Kardashian West says tearfully, as she recalls breaking the news to the