added a bit in the docs about specifying a physical type to the decorator
added a bit in the docs about specifying a physical type to the decorator

stargaser/astropy,astropy/astropy,larrybradley/astropy,kelle/astropy,mhvk/astropy,MSeifert04/astropy,DougBurke/astropy,stargaser/astropy,StuartLittlefair/astropy,larrybradley/astropy,funbaker/astropy,StuartLittlefair/astropy,DougBurke/astropy,kelle/astropy,bsipocz/astropy,AustereCuriosity/astropy,AustereCuriosity/astropy,bsipocz/astropy,saimn/astropy,kelle/astropy,aleksandr-bakanov/astropy,funbaker/astropy,dhomeier/astropy,MSeifert04/astropy,astropy/astropy,lpsinger/astropy,DougBurke/astropy,mhvk/astropy,astropy/astropy,pllim/astropy,lpsinger/astropy,bsipocz/astropy,astropy/astropy,aleksandr-bakanov/astropy,stargaser/astropy,lpsinger/astropy,lpsinger/astropy,dhomeier/astropy,saimn/astropy,mhvk/astropy,saimn/astropy,mhvk/astropy,dhomeier/astropy,pllim/astropy,dhomeier/astropy,kelle/astropy,larrybradley/astropy,astropy/astropy,pllim/astropy,aleksandr-bakanov/astropy,AustereCuriosity/astropy,mhvk/astropy,DougBurke/astropy,larrybradley/astropy,StuartLittlefair/astropy,funbaker/astropy,pllim/astropy,saimn/astropy,MSeifert04/astropy,dhomeier/astropy,pllim/astropy,aleksandr-bakanov/astropy,larrybradley/astropy,MSeifert04/astropy,lpsinger/astropy,StuartLittlefair/astropy,bsipocz/astropy,stargaser/astropy,StuartLittlefair/astropy,AustereCuriosity/astropy,saimn/astropy,AustereCuriosity/astropy,kelle/astropy,funbaker/astropy