Make email pattern work in new context

The email pattern looked a bit shonky when displayed in a narrower column. This
commit fixes it by making the email’s metadata (eg subject, from) into a table,
which it sort of is. This means that it is more flexible about the size of
container in which it sits.

app/templates/views/choose-email-template.html

@@ -29,7 +29,7 @@
     {% endif %}
 
     <p>
-      <a href="{{ url_for('.add_service_template', service_id=service_id, template_type='sms') }}" class="button">Add a new template</a>
+      <a href="{{ url_for('.add_service_template', service_id=service_id, template_type='email') }}" class="button">Add a new template</a>
     </p>
 
   </form>