Don’t deep link to our support form

By deep linking to the support form we skip the question that asks if
someone is a member of the public.

This seems like a helpful thing when we’re directing people to where
they can ask for document download to be switched on. But what I think
is happening (backed up from one example I can see in Kibana):

1. Someone searches for something like ‘email GOV.UK’
2. They land on https://www.notifications.service.gov.uk/features/email
3. They scan the page and think, hmm not sure what this is, I’m not
   seeing what I’m looking for here…
4. …but aha, there’s a link that says ‘contact us’
5. They click it and land on
   https://www.notifications.service.gov.uk/support/ask-question-give-feedback
   which has a nice big box to type in

This commit removes these deep links from non-logged-in pages, so that
everyone has to go through the ‘are you a member of the public’ question
before they get to the big typey box.

app/templates/views/features/emails.html

@@ -35,7 +35,7 @@
     <!--<li>you can track when the recipient downloads your document</li>-->
     <li>email attachments are often marked as spam</li>
   </ul>
-  <p><a class="govuk-link govuk-link--no-visited-state" href="{{ url_for('.feedback', ticket_type='ask-question-give-feedback') }}">Contact us</a> if you want to send files by email.</p>
+  <p><a class="govuk-link govuk-link--no-visited-state" href="{{ url_for('.support') }}">Contact us</a> if you want to send files by email.</p>
   <p>Read our <a class="govuk-link govuk-link--no-visited-state" href="{{ url_for('.documentation') }}">API documentation</a> for more information.</p>
 
   <h3 class="heading heading-small" id="reply-to">Add a reply-to address</h3>