address PR review feedback

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

chronicle/release/releasers/github/summarizer_test.go

@@ -1451,7 +1451,6 @@ func gitTagCommit(t *testing.T, path, tag string) string {
 func gitHeadCommit(t *testing.T, path string) string {
 	t.Helper()
 
-	// why the ~1? we want git log to return inclusive results
 	cmd := exec.Command("git", "--no-pager", "rev-parse", "HEAD")
 	cmd.Dir = path
 	output, err := cmd.Output()

internal/git/first.go

@@ -12,11 +12,14 @@ func FirstCommit(repoPath string) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("unable to open repo: %w", err)
 	}
+
 	iter, err := r.Log(&git.LogOptions{})
 	if err != nil {
 		return "", fmt.Errorf("unable to log commits: %w", err)
 	}
 
+	// the iterator works just like "git log", which is in reverse chronological order. That means the
+	// first commit in the repo is the last item in the iterator.
 	var last string
 	err = iter.ForEach(func(c *object.Commit) error {
 		if c != nil {