Enable full screen option on videos under documentation

E.g. https://wordpress.github.io/wordpress-playground/quick-start-guide

The full screen option is always disabled. 

<img width="774" alt="Image" src="https://github.com/user-attachments/assets/88f7688c-e807-4fa4-85e0-09d4cee2cec0" />