minor doc updates
minor doc updates

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