Change docs link style in group CI settings

Change from a question mark to a learn more link.

Changelog: changed

app/views/groups/settings/ci_cd/_form.html.haml

@@ -8,6 +8,5 @@
           = f.number_field :max_artifacts_size, class: 'form-control'
           %p.form-text.text-muted
             = _("The maximum file size in megabytes for individual job artifacts.")
-            = link_to sprite_icon('question-o'), help_page_path('user/admin_area/settings/continuous_integration', anchor: 'maximum-artifacts-size'), target: '_blank'
-
+            = link_to s_('Learn more.'), help_page_path('user/admin_area/settings/continuous_integration', anchor: 'maximum-artifacts-size'), target: '_blank', rel: 'noopener noreferrer'
         = f.submit _('Save changes'), class: "btn gl-button btn-confirm"