[feature]: (github) repository governance setup

[edyrkaj]

This PR establishes comprehensive repository governance for GenAssist, including branch protection rules documentation, contributing guidelines, and standardized PR/issue templates personalized for Ritech and the GenAssist platform.

💡 Motivation

As GenAssist is now open source, we need clear governance structures to:

• Guide contributors on how to contribute effectively
• Standardize pull request and issue reporting processes
• Document branch protection rules for maintainers
• Ensure consistent code quality and review processes
• Provide Ritech-specific context and considerations (multi-tenant architecture, security standards)

📋 Requirements

• Document branch protection rules for GitFlow workflow
• Create comprehensive contributing guidelines
• Provide PR templates for different change types (feature, bugfix, core, improvement)
• Create issue templates for bug reports, feature requests, and improvements
• Personalize all templates with Ritech branding and GenAssist context
• Include Ritech-specific considerations (multi-tenant, security standards)

🔨 Implementation Details

Changes Made

• Added .github/BRANCH_PROTECTION.md - Comprehensive branch protection rules documentation
• Added CONTRIBUTING.md - Complete contributor guide with GitFlow workflow
• Added .github/PULL_REQUEST_TEMPLATE/bugfix.md - Bug fix PR template
• Added .github/PULL_REQUEST_TEMPLATE/feature.md - Feature PR template
• Added .github/PULL_REQUEST_TEMPLATE/core.md - Core implementation PR template
• Added .github/PULL_REQUEST_TEMPLATE/improvement.md - Improvement PR template
• Added .github/pull_request_template.md - Default PR template fallback
• Added .github/ISSUE_TEMPLATE/bug_report.md - Bug report template
• Added .github/ISSUE_TEMPLATE/feature_request.md - Feature request template
• Added .github/ISSUE_TEMPLATE/improvement.md - Improvement suggestion template
• Added .github/ISSUE_TEMPLATE/config.yml - Issue template configuration

Technical Approach

• GitFlow Strategy: Documented and implemented GitFlow branching strategy with main, development, feature/*, release/*, and hotfix/* branches
• Branch Protection: Configured rules requiring 2 approvals for main, 1 approval for development, with optional CI checks
• Template Structure: Used GitHub's standard template format for maximum compatibility