As the holiday grows with greeting cards and citywide celebrations, some wonder whether it's losing the intimacy that once fueled it ON the table are children's books. Not Dick and Jane. Not Judy Blume. These are Afrocentric volumes about Kwanzaa, colorful hardcovers and paperbacks featuring dark-skinned children in African dress. "Look at these," Angela Lindsey says to her kids, Chrishonta, 10, and Jaques, 4, while at the SHAPE Community Center recently. "These are nice." Nice, but no sale. She's not there to buy Kwanzaa material. The single parent is a Houston Community College student and needs to use a computer....