fix(example): fix dialog-form onsubmit

[rhanlin]

🔗 Linked issue

close 872

❓ 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

1. Add the form’s id to make sure the correct form responds when the submit button is clicked.
2. According to vee-validate’s documentation on handling forms, submitForm causes the page to "reload," so use handleSubmit instead to handle form submission.

📸 Screenshots (if appropriate)

📝 Checklist

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

[sadeghbarati]

Thanks ❤️

Since it's related to the docs, will mark the commit as docs: