Add PDF helper text to Let's Encrypt ToS URL

app/views/admin/application_settings/_pages.html.haml

@@ -30,6 +30,6 @@
         = f.check_box :lets_encrypt_terms_of_service_accepted, class: 'form-check-input'
         = f.label :lets_encrypt_terms_of_service_accepted, class: 'form-check-label' do
           - terms_of_service_link_start = '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: lets_encrypt_terms_of_service_admin_application_settings_path }
-          = _("I have read and agree to the Let's Encrypt %{link_start}Terms of Service%{link_end}").html_safe % { link_start: terms_of_service_link_start, link_end: '</a>'.html_safe }
+          = _("I have read and agree to the Let's Encrypt %{link_start}Terms of Service%{link_end} (PDF)").html_safe % { link_start: terms_of_service_link_start, link_end: '</a>'.html_safe }
 
   = f.submit _('Save changes'), class: "btn btn-success"

locale/gitlab.pot

@@ -8440,7 +8440,7 @@ msgstr ""
 msgid "I forgot my password"
 msgstr ""
 
-msgid "I have read and agree to the Let's Encrypt %{link_start}Terms of Service%{link_end}"
+msgid "I have read and agree to the Let's Encrypt %{link_start}Terms of Service%{link_end} (PDF)"
 msgstr ""
 
 msgid "I'd like to receive updates via email about GitLab"