DOC: array(obj, dtype=dt) can downcast (#13673)
DOC: array(obj, dtype=dt) can downcast (#13673)

* update downcasting docs
jorisvandenbossche/numpy,simongibbons/numpy,grlee77/numpy,MSeifert04/numpy,MSeifert04/numpy,jorisvandenbossche/numpy,seberg/numpy,jorisvandenbossche/numpy,pbrod/numpy,numpy/numpy,jakirkham/numpy,pdebuyl/numpy,pizzathief/numpy,numpy/numpy,mhvk/numpy,numpy/numpy,rgommers/numpy,pizzathief/numpy,anntzer/numpy,MSeifert04/numpy,jakirkham/numpy,MSeifert04/numpy,mhvk/numpy,ahaldane/numpy,abalkin/numpy,endolith/numpy,madphysicist/numpy,grlee77/numpy,WarrenWeckesser/numpy,anntzer/numpy,simongibbons/numpy,simongibbons/numpy,ahaldane/numpy,mattip/numpy,ahaldane/numpy,jakirkham/numpy,numpy/numpy,mhvk/numpy,WarrenWeckesser/numpy,seberg/numpy,jorisvandenbossche/numpy,charris/numpy,pbrod/numpy,endolith/numpy,mhvk/numpy,grlee77/numpy,pdebuyl/numpy,abalkin/numpy,jakirkham/numpy,anntzer/numpy,rgommers/numpy,pdebuyl/numpy,grlee77/numpy,seberg/numpy,madphysicist/numpy,charris/numpy,ahaldane/numpy,rgommers/numpy,mattip/numpy,pizzathief/numpy,seberg/numpy,simongibbons/numpy,rgommers/numpy,WarrenWeckesser/numpy,pbrod/numpy,mhvk/numpy,jorisvandenbossche/numpy,pdebuyl/numpy,pizzathief/numpy,charris/numpy,ahaldane/numpy,simongibbons/numpy,madphysicist/numpy,madphysicist/numpy,grlee77/numpy,pbrod/numpy,jakirkham/numpy,mattip/numpy,MSeifert04/numpy,WarrenWeckesser/numpy,endolith/numpy,pbrod/numpy,endolith/numpy,charris/numpy,mattip/numpy,WarrenWeckesser/numpy,abalkin/numpy,madphysicist/numpy,anntzer/numpy,pizzathief/numpy