Add CODE_OF_CONDUCT.md for community guidelines

[Yusufolosun]

Objective
Establish clear community guidelines and code of conduct to foster an inclusive, welcoming environment for all contributors to the SplitStream Protocol project.

Requirements

Standard to Follow

• Use the Contributor Covenant v2.1 as the foundation
• Customize contact information for enforcement
• Align with project values and goals

Key Sections Required

1. Our Pledge - Commitment to inclusive environment
2. Our Standards - Expected vs unacceptable behavior
3. Enforcement Responsibilities - Community leader duties
4. Scope - Where code applies (repos, events, social media)
5. Enforcement - Reporting process and consequences
6. Enforcement Guidelines - Impact assessment framework
7. Attribution - Credit to Contributor Covenant

Customization Needed

• Add project-specific contact email for violations
• Include GitHub-specific guidelines (issue etiquette, PR behavior)
• Reference CONTRIBUTING.md for technical collaboration guidelines
• Add section on respectful technical disagreements

Integration

• Link from README.md
• Reference in CONTRIBUTING.md
• Add to GitHub community health files

Acceptance Criteria

• CODE_OF_CONDUCT.md created in project root
• Based on Contributor Covenant v2.1
• Includes enforcement contact information
• Covers all standard sections
• Referenced in README and CONTRIBUTING
• Clear, professional, and enforceable guidelines