Introduce CHANGELOG.md file

[mfogliatto]

Description

We need to introduce a CHANGELOG.md file to track changes between versions and provide users with clear information about updates, new features, and bug fixes.

Problem

Without a proper changelog, it's difficult for users and contributors to understand what has changed between versions, which features have been added, and which bugs have been fixed.

Proposed Solution

1. Create a CHANGELOG.md file in the root of the repository
2. Document changes for previous releases (if feasible)
3. Establish a process for updating the changelog with new releases

Implementation Details

• Use the Keep a Changelog format
• Include sections for Added, Changed, Deprecated, Removed, Fixed, and Security
• Link to GitHub issues and pull requests where appropriate
• Maintain the changelog for all future releases

Acceptance Criteria

• CHANGELOG.md file exists in the repository root
• Format is clear, consistent, and follows established practices
• Recent changes are documented with appropriate details
• Process is in place for maintaining the changelog with future releases