Capitalize first letter after colon

Author: ianjmacintosh

exercises/05.typescript/README.mdx

@@ -125,7 +125,7 @@ Don't worry if you struggle with TypeScript at first, the more you use it, the
 better you'll get at it, just like anything else.
 
 <callout-info>
-	Note: we're moving from the `*.html` files to `*.tsx` files. This is more
+	Note: We're moving from the `*.html` files to `*.tsx` files. This is more
 	real-world and also your editor likely supports TypeScript better within
 	TypeScript files rather than HTML files. From here on out, the `index.tsx`
 	file will be loaded onto the page automatically. We'll also get live reload of