Jonny Donahoe walks around the theater dropping notes on the audience members’ laps as you are seated for Every Brilliant Thing. “Oh, you are the star, right?” observed a man picking up his paper. “I am the play,” said Donahoe. Well, not quite. I hope it is not revealing too much to say that his supporting cast is you, if you are adventurous enough to attend this brisk hour of an uplifting, funny play on a potentially grim subject. Author of this engaging night of theater with Duncan Macmillan, Donahoe treats the delicate subject of a suicidal mother and a son’s attempts to cheer her into life by listing as many brilliant things as can be imagined.