When Kenneth Wehr started managing the Greenlandic-language version of Wikipedia four years ago, his first act was to delete almost everything. It had to go, he thought, if it had any chance of surviving. Wehr, who’s 26, isn’t from Greenland—he grew up in Germany—but he had become obsessed with the island, an autonomous Danish territory, after visiting as a teenager. He’d spent years writing obscure Wikipedia articles in his native tongue on virtually everything to do with it. He even ended up ...