Dylan Siegel goes beyond what many first graders might do for a pal. Siegel, a 6-year-old from Los Angeles, wrote a book called “Chocolate Bar” to raise money for research into what ails his best friend, Jonah Pournazarian. Jonah, 7, suffers from a one-in-a-million liver disease called glycogen storage disease type 1B. There is no cure. […]