Proposed CHANGELOG.md file format

Purpose

New CHANGELOG.md file format to help provide history of significant changes for users / devs
- Why a CHANGELOG when you have packaged releases? Packaging systems come and go, but a changelog is for the long-term.
- Suggested update strategy is: https://semver.org whenever committed to main branch
Leveraging https://keepachangelog.com/en/1.0.0/ format
⚠ NOTE: this is a "draft" pull request, please commit to this PR branch with your existing release information to the changelog before merging
Proposed Changes
[ADD] CHANGELOG.md file with sample content
Testing
For live example, see: https://github.com/olivierlacan/keep-a-changelog/blob/main/CHANGELOG.md