doc fixes in coordinates as suggested by @taldcroft
doc fixes in coordinates as suggested by @taldcroft

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