Britney Spears has landed a multi-million-dollar book deal for a tell-all memoir about her relationship with her family, living under a conservatorship for more than a decade, and her rise to stardom. The pop star, 40, signed the landmark deal with publisher Simon & Schuster, with the contract valued at more than $15 million, sources close to Spears told media outlets. “The deal is one of the biggest of all time, behind the Obamas,” an unnamed source told Page Six, which was first to report on the book deal. In 2017, former President Barack Obama and First Lady Michelle Obama signed a $65 million deal with Penguin Random House to author several books. The Epoch Times has reached out to Simon & Schuster for comment. The book deal comes after a Los Angeles judge in November dissolved the controversial conservatorship, which had been put in place by her father, Jamie …