Adding multi-key docs to Cache methods.
Adding multi-key docs to Cache methods.

pixelcog/lithium,muyehub/lithium,m4rcsch/lithium-core-library,m4rcsch/lithium-core-library,UnionOfRAD/lithium,graphis/lithium,wbeater/lithium,UnionOfRAD/lithium,wbeater/lithium,muyehub/lithium,whowgames/lithium,davidpersson/lithium,datachand/lithium,jails/lithium,davidpersson/lithium,pixelcog/lithium,jails/lithium,whowgames/lithium,datachand/lithium,graphis/lithium