Four months after falling 11 games under .500, the New York Mets earned a playoff berth a day after the regular season was supposed to end. With a thrilling 8-7 win over the Atlanta Braves in the opener of a makeup doubleheader behind Francisco Lindor’s two-run homer in the ninth inning, the Mets advanced to a best-of-three NL Division Series starting Tuesday at Milwaukee. New York overcame an 0-5 start to reach the postseason for the 11th time in the team’s 63 seasons.