add example numbers to docs for light_travel_time
add example numbers to docs for light_travel_time

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