Maintain a changelog file

[jooola]

I find it difficult to understand and track the changes made in Molecule with the current changelog posted on the Github release page.

The changes described in the release page are not enough from both a user and developer perspective.

Migrations instructions or breaking changes are not properly documented, for example this commit 21dcd2b is "Removing support for custom templating from drivers", but this is not detailed in the GitHub release page.

That said, as a developer, I have no problem browsing the commit history, even though it's not as friendly as a changelog.

I would like to propose that this project starts to maintain a changelog file and use tools to help.