docs: add live demo link to voice translation notebook

[cristim67]

Summary

Add live demo link to voice translation notebook to help users quickly test and understand the capabilities.

Motivation

While the notebook provides comprehensive instructions for implementing voice translation, having access to a live demo allows users to:

• Immediately experience the end result before diving into implementation
• Better understand the potential applications

Adding this demo link enriches the educational value of the cookbook by bridging the gap between theory and practical application. The demo at audio-translator.genez.io serves as a perfect companion to the technical implementation detailed in the notebook.

For new content

When contributing new content, read through our contribution guidelines, and mark the following action items as completed:

• [ ] I have added a new entry in registry.yaml (and, optionally, in authors.yaml) so that my content renders on the cookbook website.
• [x] I have conducted a self-review of my content based on the contribution guidelines:
• [x] Relevance: The demo link directly relates to OpenAI's GPT-4 audio capabilities and provides practical value to users
• [x] Uniqueness: I verified that no other voice translation example in the cookbook currently includes this demo reference
• [x] Spelling and Grammar: The added text has been checked for correct spelling and grammar
• [x] Clarity: The demo link is presented clearly and fits naturally within the document flow
• [x] Correctness: The demo link has been verified to be functional and points to the correct resource
• [x] Completeness: The addition includes all necessary context for users to understand and access the demo

We will rate each of these areas on a scale from 1 to 4, and will only accept contributions that score 3 or higher on all areas. Refer to our contribution guidelines for more details.