Michael Appler The chandelier inside the Majestic Theater — the iconic gold fixture that plummets into the audience as the “The Phantom of the Opera” reaches its act one climax — is still dark, and it’ll stay that way until at least the end of October. But on Monday evening, the theater community gathered at the Majestic — the first time in more than 500 days that the Broadway theater opened its doors — to celebrate the premiere of “The Show Must Go On,” a new documentary chronicling the