Support customizing the tag header link in the changelog

[cabauman]

Current behavior: links to the tag page (example)

With standard-version, clicking on the version link in the changelog takes you to a nice diff page (example)

Maybe we should consider supporting both? .versionrc supports customizing the comparison link because it differs between providers. As an example here's the format for Bitbucket:

"compareUrlFormat": "{{host}}/{{owner}}/{{repository}}/compare/{{currentTag}}..{{previousTag}}"

Current and previous tag are reversed for Bitbucket and GitHub.

[petro-konopelko]

We would like to also have this feature to overwrite default link to release. Currently in the Azure devops it leads to the unknow page.
Current link
$"https://{_organization}@dev.azure.com/{_organization}/{_repository}/releases/tag/v{version}";
Our link to tag
$"https://{_organization}@dev.azure.com/{_organization}/{_repository}?version=GTv{version}";
So it would be great to provide custom configuration for the link format. And in that case it will be possible to pass link of comparison between tags