docs: Wrap full example in accordion component

Author: beran-t

docs/examples/app-preview.mdx

@@ -112,6 +112,7 @@ for entry in report:
 
 ## Full example
 
+<Accordion title="View full code">
 ```python app_preview.py
 """
 App Preview — E2B + Kernel
@@ -250,6 +251,7 @@ def main():
 if __name__ == "__main__":
     main()
 ```
+</Accordion>
 
 ## Key concepts