Add section on configuration in deprecation/backwards-incompatible changes
Add section on configuration in deprecation/backwards-incompatible changes

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