[useSetState] Consider adding a default value to `initialState` (emptyObj)

[kaitoukid-1412]

hooks/packages/hooks/src/useSetState/index.ts

Line 10 in c7bb04c

initialState: S | (() => S),

https://github.com/streamich/react-use/blob/ad33f76dfff7ddb041a9ef74b80656a94affaa80/src/useSetState.ts#L4