The Glamour x Catbird exclusive The mere mention of the word Catbird around our offices is guaranteed to garner an unadulterated sigh of glee—and we're not the only ones. Visit the tiny Williamsburg shop any day of the week and you'll find it overflowing with trendsetters; you might even spot A-listers like Michelle Williams, Lena Dunham, and Elizabeth Olsen among the die-hard fans. So enamored are we with the brand's sweet-meets-street aesthetic—it started the layered knuckle ring…