SPEC.md: acVersion compatibility of pod and image
SPEC.md: acVersion compatibility of pod and image

and requirement for it to be populated and semver format

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