Create CODE OF CONDUCT

[manghidev]

This pull request introduces a CODE_OF_CONDUCT.md file to establish community standards and guidelines for behavior. It outlines acceptable and unacceptable behaviors, enforcement responsibilities, and the consequences of violations to foster a welcoming and inclusive environment.

Key additions:

• Added a detailed Code of Conduct based on the Contributor Covenant, version 2.0, to promote a harassment-free and inclusive community.
• Defined enforcement responsibilities for community leaders, including their authority to moderate contributions and enforce standards.
• Established enforcement guidelines with a tiered system of consequences for violations, ranging from warnings to permanent bans.
• Included attribution to the Contributor Covenant and Mozilla's enforcement ladder, along with links to additional resources and FAQs.