The annual PBS Kids’ Writing Contest is underway, and the deadline is Friday, March 29. It’s for children in kindergarten through third grade. Participants submit both stories and illustrations, and the winning stories air on GPB TV. This year, we’ll also air some during “On Second Thought.” Two Georgia children’s book writers are helping to inspire kids to participate. Aisha Saeed is author of “Bilal Cooks Daal," and Laurel Snyder’s books include “The King of Too Many Things” and “Charlie and