Why necessarily bug if github refernce in message?

[hlibbabii]

Why necessarily bug if github refernce in message? Can't it be reference to feature or enhancement?

@Heuristic(Commit)
def github_ref_in_message(commit: Commit) -> Optional[Labels]:
    """
    >>> github_ref_in_message(Commit("x", "y", "12afbc4564ba", "gh-123: bug"))
    CommitLabel.BugFix
    >>> github_ref_in_message(Commit("x", "y", "12afbc4564ba", "gh 123"))
    CommitLabel.BugFix
    >>> github_ref_in_message(Commit("x", "y", "12afbc4564ba", "GH 123: bug2"))
    CommitLabel.BugFix
    >>> github_ref_in_message(Commit("x", "y", "12afbc4564ba", "GH123: wrong issue reference")) is None
    True
    """
    return CommitLabel.BugFix if GITHUB_REF_RE.search(commit.message.raw) else None