[release]: Updates README.
[release]: Updates README.

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