improve clarity and consistency of toggleTask example with rest of doc (#1205)

Author: chrisbirster

src/routes/guides/complex-state-management.mdx

@@ -196,7 +196,7 @@ import { produce } from "solid-js/store"
 const toggleTask = (id) => {
 	setState(
 		"tasks",
-		(tasks) => tasks.id === id,
+		(task) => task.id === id,
 		produce((task) => {
 			task.completed = !task.completed
 		})
@@ -262,7 +262,7 @@ const App = () => {
 	const toggleTask = (id) => {
 		setState(
 			"tasks",
-			(tasks) => tasks.id === id,
+			(task) => task.id === id,
 			produce((task) => {
 				task.completed = !task.completed
 			})