Add link to the note when adding a comment on an issue

app/views/notify/_note_email.html.haml

@@ -9,7 +9,7 @@
   = succeed ':' do
     = link_to note.author_name, user_url(note.author)
     - if discussion.nil?
-      commented
+      = link_to 'commented', target_url
     - else
       - if note.start_of_discussion?
         started a new

changelogs/unreleased/jduplessis_issue_comment_link.yml

+---
+title: Add link to the note when adding a comment on an issue
+merge_request: 45511
+author:
+type: changed

spec/mailers/notify_spec.rb

@@ -619,6 +619,7 @@ RSpec.describe Notify do
       let(:mailer) do
         mailer = described_class.new
         mailer.instance_variable_set(:@note, mail_thread_note)
+        mailer.instance_variable_set(:@target_url, "https://some.link")
         mailer
       end