docs: Enhance organization profile and add community health files

[GuDevBot]

What this PR does

This Pull Request introduces and enhances key community health files in the .github repository. Specifically, it:

1. Revamps the profile/README.md to serve as a proper and welcoming landing page for the organization.
2. Adds a root README.md to explain the purpose of this special repository.
3. Adds a central CONTRIBUTING.md file to standardize and clarify the contribution process.
4. Adds a CODE_OF_CONDUCT.md based on the Contributor Covenant.
5. Adds a SECURITY.md to provide a clear policy for reporting vulnerabilities.

Why this change is important

These changes significantly improve the contributor experience and project professionalism by:

• Lowering the barrier for new contributors.
• Aligning the organization with open-source best practices.
• Providing clear, centralized guidelines for community interaction and contribution.
• Creating a more welcoming and professional first impression for anyone visiting the organization's GitHub page.

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For Maintainers: Next Steps

To complete this setup, the following action is recommended:

• Update the Code of Conduct Link: The CONTRIBUTING.md file contains a link to the CODE_OF_CONDUCT.md. This PR creates the file, so the link should now be functional. A quick verification would be great.
• Update Security Email: The SECURITY.md file suggests [email protected]. Please verify if this is the correct contact.