A yoga instructor was axed from a Manhattan school for repeatedly engaging in “inappropriate” behavior with a 6-year-old student, a bombshell investigation has revealed. Demetrius Napolitano, 31, the founder and owner of Harlem-based nonprofit Fostering Meditation, was allegedly touchy with the young girl who attended PS 108 on Madison Avenue while he taught yoga classes there under a contract with the city Department of Education. Napolitano allegedly repeatedly hugged the child and carried