fix: Fix bug where an initialInstanceState of type function always ge…

…ts called every render

closes #1

index.js

@@ -1,12 +1,12 @@
 import { useState, useMemo } from "react";
 
 export default function useInstance(initialInstanceState) {
-  const [{ instance }, updateInstance] = useState({
+  const [{ instance }, updateInstance] = useState(() => ({
     instance:
       typeof initialInstanceState === "function"
         ? initialInstanceState()
         : initialInstanceState
-  });
+  }));
   return useMemo(() => [
     instance,
     function update() {