For three decades, Fred Rogers slipped into a cardigan and slipped into our hearts.The gentle philosopher invited generations of viewers into his television neighborhood of working-class friends like delivery man Mr. McFeely and Handyman Negri — then onto a trolley for a ride into the Neighborhood of Make-Believe, ruled by King Friday XIII and Queen Sara Saturday.Along the way, the real-life ordained minister would impart lessons about self-worth and belonging, as well as tough topics ranging from the death of his goldfish to divorce, anger and war.“‘Won’t you be my neighbor?’ It’s an invitation for somebody to be close to you,” Rogers, who died in 2003, says in the documentary bearing his catch phrase.