[OPR-100]: + docs to GroupOperation
[OPR-100]: + docs to GroupOperation

blg-andreasbraun/Operations,danthorpe/Operations,blg-andreasbraun/Operations,danthorpe/Operations,blg-andreasbraun/Operations,ProcedureKit/ProcedureKit,blg-andreasbraun/ProcedureKit,cezarywojcik/Operations,blg-andreasbraun/ProcedureKit,ProcedureKit/ProcedureKit,cezarywojcik/Operations,cezarywojcik/Operations,blg-andreasbraun/ProcedureKit,ProcedureKit/ProcedureKit,danthorpe/Operations