Trailing clouds of glitter from a surprise Broadway triumph in Kenneth Lonergan’s serio-comedy This Is Our Youth, Rookie magazine founder Tavi Gevinson has expanded her extensive resume to include publishing maven. In addition to compiling the fourth Rookie Yearbook, due out this fall, Gevinson just made her debut as a literary editor. In the July/August issue of Poetry, the 103-year-old magazine that introduced American readers to the likes of Ezra Pound, Langston Hughes, and Edna St. Vincent Millay,…