This was the subject line of an ultimatum email Chief Twit (Elon Musk) sent to the remaining Twitter employees during the night Tuesday (does he ever sleep?) “lf you are sure that you want to be part of the new Twitter, please click yes on the link below,” Musk wrote. “Anyone who has not done so by 5pm ET tomorrow (Thursday) will receive three months of severance. Whatever decision you make, thank you for your efforts to make Twitter successful.” The email, sent late Tuesday night or early Wednesday morning, was first reported by The Washington Post and later by CNN. A screenshot…