Support non-semVer

I found this library while looking to an alternative of [clparse](https://github.com/marcaddeo/clparse) (which I was recommended at https://github.com/NiclasvanEyk/keepac/issues/20#issuecomment-1712944920).

My tool is not using SemVer, but using keep-a-changelog-format. Example: https://github.com/JabRef/jabref/blob/v5.11/CHANGELOG.md. I am also using en dashes for separation (so that the CHANGELOG.md looks nicer to end users).

https://github.com/colindean/keepachangelog-parser-java seems to enforce SemVer.

Just wanted to let you know about this.

Think, I will continue working on [heylogs](https://github.com/nbbrd/heylogs#heylogs). While keepachangelog-java-parser has a better internal data model, heylogs offers more functionality. Still working on getting it implementing my wish (https://github.com/nbbrd/heylogs/pull/146).