Improve guidance_prompt. Cleanup code

app.py

@@ -428,6 +428,7 @@ follows the rules defined in the guidlines. Make sure to preserve the structure
 original text as much as possible. Do not modify the structure of the original text.
 Do not change the language of the original text.                     
 Output only the modified text in markdown format.
+Do not add any preceding or trailing text to the output.
 
 Product description: 
 {text}