add note about accuracy
add note about accuracy

saimn/astropy,lpsinger/astropy,larrybradley/astropy,lpsinger/astropy,StuartLittlefair/astropy,lpsinger/astropy,astropy/astropy,mhvk/astropy,saimn/astropy,mhvk/astropy,mhvk/astropy,mhvk/astropy,astropy/astropy,pllim/astropy,pllim/astropy,StuartLittlefair/astropy,saimn/astropy,larrybradley/astropy,saimn/astropy,astropy/astropy,saimn/astropy,StuartLittlefair/astropy,larrybradley/astropy,astropy/astropy,aleksandr-bakanov/astropy,pllim/astropy,pllim/astropy,lpsinger/astropy,aleksandr-bakanov/astropy,StuartLittlefair/astropy,mhvk/astropy,larrybradley/astropy,astropy/astropy,aleksandr-bakanov/astropy,larrybradley/astropy,lpsinger/astropy,aleksandr-bakanov/astropy,StuartLittlefair/astropy,pllim/astropy