Reed Timmer is arguably the most recognizable storm chaser in the world, known for his fearless enthusiasm as he willingly drives directly toward tornadoes with his team in one of his heavily armored “Dominator” vehicles. In the pulse-pounding documentary “Never Stop Chasing,” Timmer’s exploits are expanded from his decades-long presence on the Discovery Channel and YouTube and the like, to the big screen. Even given the devastating run of storms that have pounded the Midwest this summer, this is the closest MOST of us will get to a tornado, and thank God for that.