docs: Add llms.txt and llms-full.txt

[KrzysztofMoch]

Summary

Adds scripts to automatically generate documentation files tailored for Large Language Models (LLMs) and other automated systems. This enhancement provides structured, up-to-date project information and documentation.

• Generates llms.txt: Creates a concise overview of the project, including features, project status, key concepts, and usage examples.
• Generates llms-full.txt: Compiles a comprehensive version by concatenating the main README and all detailed documentation pages.

This automation ensures that LLM-friendly content remains current with codebase changes, improving AI-assisted understanding and information retrieval for developers and users.

You can access those files at:

• https://docs.thewidlarzgroup.com/react-native-video/llms.txt
• https://docs.thewidlarzgroup.com/react-native-video/llms-full.txt

Continuation of #4588