Sylvester Stallone’s upcoming memoir is said to be like Matthew McConaughey and Arnold Schwarzenegger’s self-help style autobiographies. The ‘Rocky’ actor, 77, is releasing his life story ‘The Steps’ – inspired by his famed “Rocky” character’s running up the Philadelphia Museum of Art’s steps in the 1976 film’s iconic training montage – by 2025 through Harper HarperCollins’ imprint William Morrow, which is said to have won the rights to the book in a heated auction, according to Page Six. It has also reported the memoir is “drawing parallels” to Matthew McConaughey’s ‘Greenlights’ and Arnold S…