DEAR READERS: I’m happy to take a tiny break from hosting your questions, as I devote this column to my annual literacy campaign, now in its 13th year. This is where I urge readers to celebrate the gift-giving season by putting “A Book on Every Bed.” All literacy starts with a story, and the inspiring story behind this effort came to me from Pulitzer Prize-winning historian David McCullough, whose charmed and productive life was entirely shaped by the sharing of books and stories, starting early in his childhood. Mr. McCullough died this past August at the age of 89, and many of the tributes t…