Lil Yachty has shared two new singles, “Harley” and “Peek a Boo,” the latter of which features Migos. The songs find the Atlanta rapper at his typical, whimsical best, with singsongy hooks and rapid-fire verses over tight, bass-heavy production. They are his first solo singles since his feature on Kyle’s “iSpy” shot up the Billboard Hot 100, and since the release of his…