✨ Add support for custom commit URLs and issue resolution

[stalinkay]

This commit introduces the ability to customize commit URLs and issue resolution in release notes. It also adds support for GitLab and Bitbucket comparison links. The changes include updates to the default configuration, release notes generation, and test cases. The commit URL is now generated using a string template, and issue references in commit messages can be resolved based on a custom configuration.

[stalinkay]

@momocow Hi, I attempted to add support for custom repos and issue resolutions. There are two failing tests that I couldn't resolve. The documentation also needs to be updated. Could you finish those bits since I'm not well versed in the details of the project?