feat: add Contributor Covenant Code of Conduct

[manghidev]

This pull request adds a new CODE_OF_CONDUCT.md file to the repository, establishing clear guidelines for community behavior and outlining enforcement procedures.

Community standards and enforcement:

• Introduces a Contributor Covenant Code of Conduct, detailing expected standards of behavior and examples of unacceptable conduct for all community members.
• Defines enforcement responsibilities, scope, reporting process, and a tiered system of consequences for violations, including correction, warning, temporary ban, and permanent ban.
• Adapts the code of conduct from the Contributor Covenant v2.0 and includes proper attribution and links to further resources.This document outlines the standards of behavior expected from community members and the enforcement measures for violations.