Changelog for version updates would be nice

[tapickell]

As an engineer with a project that depends on this crate
When dependa-bot creates a PR to update to the latest version
I should be able to find a Changelog that indicates what has changed between versions
So I can be sure the update will not break any functionality the app is using.

[jonaspleyer]

FYI The current new release candidate 0.6.0-rc1 introduces quite a large quantity of additions to the crate. Personally, I do not have the time to go back and provide a full changelog for all past versions. However, it is probably reasonable to do so for the future. 👍

[jonaspleyer]

Update I have added a file Changelog.md which holds all future changes.