docs: warn about modules with side-effects

[huang-julien]

🔗 Linked issue

resolve #19506

❓ Type of change

• 📖 Documentation (updates to the documentation, readme or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Hi 👋
Some users reported that some of their pages fails to render due to window being undefined. The reason is this was caused by importing modules containing side-effects. Even if the user expect the code to work because it calls the import in a onMounted, the component crash at render because the import is not treeshaken in server-side.
This pr warns about importing modules with side-effects.
Maybe can it be improved by adding an example to the error handling ? Or as mentionned by @manniL , listing a small list of modules containing side-effects (leaflet) ?

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

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