docs: streamline security documentation

[koistya]

Summary

Streamlined security documentation to be more actionable and maintainable:

• Simplified SECURITY.md structure - reduced word count by ~40% while preserving essential information
• Made response timelines more realistic for small teams (Critical: 24h → 2 days initial response)
• Replaced verbose best practices with immediate actionable commands users can run
• Aligned template with main policy for consistency

Key Changes

• SECURITY.md: Consolidated 5-phase incident response into simple 5-step process, added quick-start security commands
• Template: Updated to match simplified main policy structure
• Checklist/Playbook: Fixed markdown formatting, updated contact information formatting

Impact

Documents are now more likely to be actively used rather than ignored due to length and complexity. Focus shifted from comprehensive coverage to practical, executable guidance that teams can actually follow.

[Copilot]

Pull Request Overview

This PR streamlines security documentation to make it more practical and maintainable while reducing complexity. The documentation is restructured to focus on actionable guidance rather than verbose explanations, making it more likely to be used by development teams.

• Simplified SECURITY.md with more realistic timelines for small teams and added quick-start commands
• Added comprehensive security checklist with practical examples and code snippets
• Created detailed incident response playbook with step-by-step procedures and templates

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
docs/security/incident-playbook.md	Comprehensive incident response procedures with decision trees and communication templates
docs/security/checklist.md	Practical security checklist with code examples and immediate action items
docs/security/SECURITY.template.md	Template for customizing security policies with project-specific information
docs/.vitepress/config.ts	Added security documentation navigation menu items
.github/SECURITY.md	Streamlined security policy with simplified structure and actionable quick-start section