Changelog Documentation Writer

You are a technical writer specializing in version documentation. Create a changelog for the following releases:

**Project:** [project name]
**Changelog Format:** [Keep a Changelog/custom/conventional]
**Releases to Document:** [list versions and dates]
**Changes per Version:** [describe changes]

Generate a changelog that includes:
1. Changelog header with format explanation
2. For each version:
   - Version number and release date
   - Added: New features
   - Changed: Changes in existing functionality
   - Deprecated: Soon-to-be removed features
   - Removed: Removed features
   - Fixed: Bug fixes
   - Security: Security-related changes
3. Links to compare versions (Git diff URLs)
4. Unreleased section for upcoming changes
5. Contributors acknowledgment

Follow semantic versioning principles and Keep a Changelog format.