Translation needed for existing languages

[github-actions]

@sumn2u has made changes on the original english version of the book (PR #336)

Visual Diff of Changes:

diff --git a/en/beginner-projects/video-trailer-popup.md b/en/beginner-projects/video-trailer-popup.md
index 37ef0bc..7e22943 100644
--- a/en/beginner-projects/video-trailer-popup.md
+++ b/en/beginner-projects/video-trailer-popup.md
@@ -21,3 +21,12 @@ Create a popup modal that plays a video trailer when triggered. Perfect for movi
 Add autoplay and pause video when popup is closed.
 
 
+## Live Demo
+<div align="center">
+  <iframe src="https://codesandbox.io/embed/zsvp9c?view=preview"
+     style="width:100%; height: 500px; border:0; border-radius: 4px; overflow:hidden;"
+     title="video popup"
+     allow="accelerometer; ambient-light-sensor; camera; encrypted-media; geolocation; gyroscope; hid; microphone; midi; payment; usb; vr; xr-spatial-tracking"
+     sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
+   ></iframe>
+</div>

[sumn2u]

🌍 Welcome & Thank You!

We're excited to have you help translate our project! Your contribution will make it accessible to more people around the world.

📝 Translation Task

Please translate the book's content from our base language (English) into the language you are contributing to.

Our project already has community translations for: Turkish, Nepali, French, Indonesian, Spanish, German, and Chinese. We are now looking to add new languages or improve existing ones.

✅ Acceptance Criteria

To ensure high-quality, consistent translations, please follow these guidelines:

• Complete Coverage: All missing content from the base English files is translated
• Human-Reviewed: No machine-only translations. Please review and adjust for natural flow
• Glossary Consistency: Technical terms must match our project's glossary
• Tone Match: The style and tone should match our existing translations

🚀 How to Get Started

The content is organized in language-specific folders. Here's how to contribute:

1. Find Your Language Folder:

   • To improve an existing language (e.g., French), find the /fr/ directory
   • To add a new language, please open an issue first to discuss. You would then create a new directory (e.g., /es/ for Spanish) based on the /en/ structure

2. Work on the Files:

   • The English source files are in the /en/ directory
   • Navigate to the corresponding file in your target language folder
   • Translate any missing .md files or update existing ones
   • Tip: Focus on one file or chapter at a time for easier review

3. Submit Your Changes:

   • Once you've translated the files, submit your changes as a Pull Request

Questions? Don't hesitate to ask here! We're happy to help you get started.