The proliferation of documentaries on streaming services makes it difficult to choose what to watch. Each month, we select three nonfiction films — classics, overlooked recent docs and more — that will reward your time. ‘12 Days’ (2018) Stream it on Ovid . Rent it on Amazon and Apple TV . Earlier this year, Film at Lincoln Center held a retrospective on the great French documentarian Raymond Depardon. The remastered versions shown there aren’t streaming yet, but until then, the representative “