Add theme: Enhanced Container

[mr-cheffy]

Add theme: Enhanced Container

This PR adds a new theme to the theme library.

Theme Details

• Name: Enhanced Container
• Description: Enhanced content container with rounded borders, advanced clipping, smooth animations, and GPU-optimized rendering.
• Homepage: https://github.com/dithmar1/Enhanced-Content-Container
• Author: @dithmar1

[dithmar1]

Hi!
Thanks a lot for reviewing and publishing my theme Enhanced Container

I’ve recently pushed several improvements and updates to the code (performance tweaks, refinements, and small fixes).

What would be the correct process to submit an update to the already published theme?
Should I open a new PR or update the existing one?

Thanks again for your time and for maintaining Zen Browser!

[mr-cheffy]

Yeah, a new issue would trigger a new PR. But I do have to let you know that right now mods are under a slow code freeze so it may take time to get reviewed.