README: update to reflect spec/actool changes
README: update to reflect spec/actool changes

stufflebear/spec,alban/appc-spec,jonboulle/spec,sgotti/spec,appc/spec,tklauser/spec,dustymabe/spec,ChengTiesheng/spec,dgonyeo/spec,squeed/spec,appc/spec,iaguis/appc-spec,endocode/appc-spec,krnowak/appc-spec,3ofcoins/appc-spec,dgonyeo/spec,jonboulle/spec,marineam/spec,endocode/appc-spec,alban/appc-spec,tklauser/spec,craimbert/spec,ChengTiesheng/spec,craimbert/spec,dgonyeo/spec,stufflebear/spec,mesosphere/spec,zenlinTechnofreak/spec,zenlinTechnofreak/spec,marineam/spec,yifan-gu/spec,apcera/appc-spec,apcera/appc-spec,zenlinTechnofreak/spec,iaguis/appc-spec,yifan-gu/spec,philips/spec,krnowak/appc-spec,iaguis/appc-spec,dustymabe/spec,jonboulle/spec,craimbert/spec,philips/spec,alban/appc-spec,marineam/spec,3ofcoins/appc-spec,ChengTiesheng/spec,yifan-gu/spec,3ofcoins/appc-spec,mesosphere/spec,squeed/spec,sgotti/spec,krnowak/appc-spec,dustymabe/spec,stufflebear/spec,squeed/spec,endocode/appc-spec,tklauser/spec,apcera/appc-spec,appc/spec