📝 Use syntax highlighting in RadioGroup example

docs/pages/Components/RadioGroup.mdx

@@ -17,7 +17,7 @@ The goal of this RadioGroup component is to let users select one option from two
   -	Nest with other RadioGroup or Checkboxes. If possible, keep all the options at the same level.
 
 ## Sample Code:
-```
+```jsx
 <RadioGroup label="This is a test RadioGroup" defaultSelectedKey="A">
   <RadioButton content="Option A" buttonKey="A" />
   <RadioButton content="Option B" buttonKey="B" />