[WIP]Changelog action and documentation

[UtechtDustin]

This PR will add an Github action which checks if the changelog file was modified and adds documentation about the changelog.

[wenzhixin]

• [x] Whether we need to update the CHANGELOG

I think we can add a checklist to the pull Request template, "Whether we need to update the CHANGELOG", the default value is true.

And then, the GitHub actions get the value through the GitHub API. If it is true, check whether the new changelog format is correct, if it is false, ignore it and do not check.

[UtechtDustin]

I close this PR, because @wenzhixin want to create a magic github action :-)