Add pre-release configuration for custom tags

[minsis]

I use custom tags as read out of a project file in order to do the tagging, but I would also like to be able to use pre-preleases with it. The features of this allow for pre-release bumping with v0.0.0-branch and marking the tag as a pre-release.

But when using a custom tag none of this happens. I can't even specify if I want this to be a pre-release or not regardless of any automatic features. So, at the very least allow the marking of a pre-prelease as an input variable or something.