PARIS — Information retrieved from the “black box” data recorder of a doomed German jet shows its co-pilot repeatedly accelerated the plane before it slammed into the French Alps, investigators said Friday. France’s air accident investigation agency, BEA, provided the disturbing new details a day after a gendarme found the blackened data recorder buried in debris scattered along a mountainside ravine. Based on an initial reading of the recorder, the revelation strengthened investigators’ early suspicions that co-pilot Andreas Lubitz meant to destroy the Germanwings A320. French and German investigators are still trying to figure out why.