When the Los Angeles Review of Books Web site debuted in 2012, I thought it was quixotic and unnecessary, but its smart essays and elegant design immediately won me over.This month, the LARB gave birth to a literary magazine called the Offing. The first issue contains a chapter from James Hannaham’s fantastic new novel “Delicious Foods” and a witty piece called “The New & Selected Tweets of Eighties Man,” by Alena Smith.