DOCS: clarify object_selection
DOCS: clarify object_selection

ndawe/root_numpy,rootpy/root_numpy,rootpy/root_numpy,ndawe/root_numpy,scikit-hep/root_numpy,scikit-hep/root_numpy,scikit-hep/root_numpy,rootpy/root_numpy,ndawe/root_numpy,scikit-hep/root_numpy,rootpy/root_numpy,ndawe/root_numpy