Based on the first book in Nancy Springer’s YA Enola Holmes series—“The Case of the Missing Marquess” — about Sherlock Holmes’ precocious younger sister and the various mysteries she has to solve, Netflix’s movie adaptation of the inaugural book is an absolute delight. Charming and fleet-footed, with a dynamic sense of frisson and clever chutzpah, “Enola Holmes” is a compelling mystery and a sprightly adventure with a feminist streak that’s a perfect showcase for the winsome talents of “Stranger Things” star Millie Bobby Brown.