Fix .gitignore to allow JS dist/lib folders under examples/, adding dist/lib for realtime example

[erikakettleson-openai]

Summary

This PR updates the root .gitignore to scope the dist/ and lib/ ignore rules to the top level only. This change ensures that JavaScript/TypeScript examples within the examples/ directory can include their own dist/ and lib/ folders, which are often needed for compiled or bundled output. It also adds the necessary build output files for the voice_solutions/one_way_translation_using_realtime_api example.

Motivation

The cookbook currently assumes a Python build structure, where dist/ and lib/ are safe to ignore globally. However, JavaScript/TypeScript projects use these folders for runtime artifacts. The existing rules unintentionally suppress these files from being committed, which breaks TypeScript-based examples that rely on compiled output. This change keeps the Python build hygiene intact while enabling cross-language flexibility in examples.

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