At last: Game over. Series over. For the first time in 20 years, a D.C. team in one of the four major pro sports is moving on to the conference finals. Let that sink in. The Capitals were the last to do it, in 1998, when they eliminated the Senators in five games in the second round and then ousted the Sabres in six games to clinch their only Eastern Conference title in franchise history. With Evgeny Kuznetsov’s breakaway goal less than six minutes into overtime, Washington improved to 2-9 all-time in postseason series against the Penguins; the Capitals’ only...