fix: display comments in chronological order

The GitLab API returns issue notes sorted by created_at descending by
default. Explicitly request ascending order so comments appear oldest
first, matching the natural reading order.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Matthieu Ciappara

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Comments are now displayed in chronological order (oldest first) instead of reverse.
+
 ## [0.1.0] - 2026-04-10
 
 ### Added

bin/issue-md

@@ -220,7 +220,7 @@ module IssueFormatter
   end
 
   def append_comments(lines, client, project_path, issue_iid, img_opts)
-    notes = client.issue_notes(project_path, issue_iid, per_page: 100)
+    notes = client.issue_notes(project_path, issue_iid, per_page: 100, order_by: 'created_at', sort: 'asc')
     user_notes = notes.reject(&:system)
     return unless user_notes.any?