Missing Highlight for Newly Added Line in Tic-Tac-Toe Tutorial

[jisunipark]

I know this is a very minor issue, but I noticed there is a newly added line in the Tic-Tac-Toe tutorial that isn’t highlighted. It occurs in the second code block of the “Taking Turns” section. The line setXIsNext(!xIsNext), which is the last line of the handleClick function, is new compared to the previous code snippet, yet it isn’t highlighted.

[dai-shi]

Thanks. Feel free to send a PR!

zustand/docs/guides/tutorial-tic-tac-toe.md

Line 798 in 2e6d881

```tsx {1,48-65}