Katie Ledecky got her start in swimming because she just wanted to make friends. Her brother was eager to join a team at a pool near their house and as a 6-year-old, she tagged along. By summer’s end, the Ledecky siblings had made 100 friends ranging in age from 6 to 18. Some of them remain good friends with Katie, who went on to become the world’s best swimmer in the post-Michael Phelps era. She earned five golds and a silver at this year’s world championships in Budapest, maintaining the upward trajectory she first established as a surprise gold medalist at the 2012 London Olympics. Her dominant performance in Hungary earned Ledecky Associated Press Female Athlete of the Year honors.In balloting by U.S.