The South Orange-Maplewood School District has been added to a growing list of universities and districts under investigation by federal officials for alleged discrimination. The U.S. Department of Education’s Office for Civil Rights opened a probe into the pre-K-12 school district last week, according to its online list of schools under investigation. “An institution named on this list means that OCR has initiated an investigation of a case concerning that institution. Inclusion on the list does not mean that OCR has made a decision about the case,” the announcement said. Neither school distr…