Update docs on abstract superclasses
Update docs on abstract superclasses

lilleswing/deepchem,miaecle/deepchem,lilleswing/deepchem,lilleswing/deepchem,peastman/deepchem,peastman/deepchem,deepchem/deepchem,miaecle/deepchem,miaecle/deepchem,deepchem/deepchem