Update code.mdx

Co-authored-by: Ethan Palm <[email protected]>

Author: dks333

code.mdx

@@ -303,7 +303,7 @@ sayHello();
 
 ### Diff
 
-Use `[!code ++]` and `[!code --]` to mark added and removed lines (add single line comments to the code). You can also mark multiple lines with a single comment, such as `[!code ++:3]` or `[!code --:5]`.
+Add single line comments with `[!code ++]` and `[!code --]` to mark added and removed lines. You can also mark multiple lines with a single comment, such as `[!code ++:3]` or `[!code --:5]`.
 
 ```js Diff Example icon="code" lines
 const greeting = "Hello, World!"; // [!code ++]