Update code-splitting.md (#3294)

Author: samrobbins85

content/docs/code-splitting.md

@@ -96,7 +96,7 @@ import("./math").then(math => {
 
 When Webpack comes across this syntax, it automatically starts code-splitting
 your app. If you're using Create React App, this is already configured for you
-and you can [start using it](https://facebook.github.io/create-react-app/docs/code-splitting) immediately. It's also supported
+and you can [start using it](https://create-react-app.dev/docs/code-splitting/) immediately. It's also supported
 out of the box in [Next.js](https://nextjs.org/docs/advanced-features/dynamic-import).
 
 If you're setting up Webpack yourself, you'll probably want to read Webpack's