update example to text

Author: ethanpalm

code.mdx

@@ -325,12 +325,12 @@ function sayHello() {
 sayHello();
 ```
 
-````mdx
+````text
 ```js Diff Example icon="code" lines
-const greeting = "Hello, World!"; // [\!code ++]
+const greeting = "Hello, World!"; // [!code ++]
 function sayHello() {
-  console.log("Hello, World!"); // [\!code --]
-  console.log(greeting); // [\!code ++]
+  console.log("Hello, World!"); // [!code --]
+  console.log(greeting); // [!code ++]
 }
 sayHello();
 ```