Fix: use count() in createEffect on State Management page (#802)

Author: Sc1pex

src/routes/guides/state-management.mdx

@@ -121,7 +121,7 @@ function Counter() {
 	};
 
 	createEffect(() => {
-		setDoubleCount((prev) => prev * 2); // Update doubleCount whenever count changes
+		setDoubleCount(count() * 2); // Update doubleCount whenever count changes
 	});
 
 	return (
@@ -173,7 +173,7 @@ function Counter() {
 	};
 
 	createEffect(() => {
-		setDoubleCount((prev) => prev * 2); // Update doubleCount whenever count changes
+		setDoubleCount(count() * 2); // Update doubleCount whenever count changes
 	});
 
 	const doubleCount = () => count() * 2
@@ -295,7 +295,7 @@ function App() {
 	const squaredCount = createMemo(() => count() * count());
 
 	createEffect(() => {
-		setDoubleCount((prev) => prev * 2);
+		setDoubleCount(count() * 2);
 	});
 
 	return (