Add a note to clarify only untranslated texts are translated

Author: Yiyun333

content/en/docs/refguide/modeling/mendix-ai-assistance/translation-generator.md

@@ -27,7 +27,11 @@ Once enabled, you will find the **Generate Translations...** option in **Languag
 
 {{< figure src="/attachments/refguide/modeling/mendix-ai-assistance/translation-generator/batch-translate.png" max-width=80% >}}
 
-It helps you to translate your model to different languages for which you may not have a translation. It gives translations for the languages that you have selected, using parameters in the way that works specifically for the selected languages.
+It helps you to translate your model to different languages. It gives translations for the languages that you have selected, using parameters in the way that works specifically for the selected languages.
+
+{{% alert color="info" %}}
+Translation Generator only translates the texts that do not have a translation yet, so when their corresponding **Translation** field is empty.
+{{% /alert %}}
 
 After clicking **Generate Translations...**, you will be asked to confirm your choice and be advised to review the generated translations.