Bundle full changelog with your extension
Please bundle the full changelog with your extension.
This allows users to see all changes under the 'Version history' tab in the Marketplace (for example https://marketplace.visualstudio.com/items/ryu1kn.extension-update-reporter/changelog).
And it allows Extension Update Reporter extension to correctly display your changelog.

I'm seeing that you are bundling some sort of "mini changelog". Why is that needed?
I would advice to bundle the full CHANGELOG.md file.
On a separate note, I see that your changelog doesn't follow the Keep a Changelog guideline principles anymore after version 4.0.9.
Specifically:
- Versions and sections should be linkable.
- The release date of each version is displayed.
Another note: you might want to exclude some files when publishing:

Keeps the extension small and clean.