While sweater weather has yet to arrive throughout much of the United States, September does still mark the official beginning of autumn. Which, in the realm of entertainment, means that summer fluff has begun to give way to more substantial fare. Among this month’s TV highlights, you’ll find a vindication of gonzo investigative journalism, an unusually insightful psychological thriller, a crime drama that doubles as a meditation on forgiveness, a heavy metal docuseries that couldn’t feel less