Added missing mention of represent_as in coordinate docs
Added missing mention of represent_as in coordinate docs

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