Changed link to Django Girls mentors sign up

Author: t-redactyl

src/content/pages/beginners-day.mdx

@@ -49,7 +49,7 @@ Just bring a laptop, and by the end of the day, you'll have deployed your first
 
 We are also looking for **mentors** for Django Girls. Applications for mentors close on **July 4th**.
 
-<Button url="https://docs.google.com/forms/d/e/1FAIpQLScJeKrKmDmS8BNpcwxeEmqkeMbJvtCSyhskxGMZnba5yGYv7Q/viewform?usp=header">Become a Django Girls Mentor!</Button>
+<Button url="https://docs.google.com/forms/d/e/1FAIpQLScJeKrKmDmS8BNpcwxeEmqkeMbJvtCSyhskxGMZnba5yGYv7Q/viewform?usp=dialog">Become a Django Girls Mentor!</Button>
 
 ## Humble Data