unstableTagRegex isn't semver compliant

[Rulqu]

conventional-changelog/packages/git-client/src/ConventionalGitClient.ts

Line 94 in d3b8aaa

const unstableTagRegex = /.+-\w+\.\d+$/

This regex doesn't take into account that semver defines pre-release like this "A pre-release version MAY be denoted by appending a hyphen and a series of dot separated identifiers immediately following the patch version..." https://semver.org/#spec-item-9

Better regex could be like [1-9]\d*\.[1-9]\d*\.[1-9]\d*- so it still doesn't care about prefix but only about the hyphen after 3 numbers separated by dot.

My problem is that someone used semver compatible versioning with pre-releases as such:

v1.1.1-rc1-13
v1.1.1-rc1-14
v1.1.1-rc1-15

and the current regex doesn't catch this.

[dangreen]

@Rulqu Hi. Feel free to open PR!