SilverStripe Lesson 2 "Code repository" link results in a 404 error

<%- if @topic_view.topic.tags.present? %>
<%= t 'js.tagging.tags' %>: <%- @topic_view.topic.tags.each do |t| %> <%= t %> <%- end %>
<% end %>

Hi. I’m just starting to learn SilverStripe, and I’d like to bring to you attention that the SilverStripe Lesson 2 “Code repository” link, when clicked, brings the user to a page on Github with a 404 error. The latest SilverStripe Lesson 2 code seems to be located at GitHub - silverstripe/silverstripe-lessons-v4: The source code for the Lessons section, version 4.x.