Make blank letter template on adding

When adding a letter it’s hard to know how the stuff you’re typing is
going to look. So rather than go straight to the edit form let’s show
users a blank letter. They can then choose which part of it they want
to edit first. And will have a better idea of how their changes are
going to show up.

In research we also saw nervousness around saving a template and wanting
to ‘preview’ it first. Hopefully this flow will make people feel less
precious about saving a template because they’ve already done it once
just by creating the template.

app/main/views/templates.py

@@ -178,6 +178,22 @@ def add_template_by_type(service_id):
     )
 
     if form.validate_on_submit():
+
+        if form.template_type.data == 'letter':
+            blank_letter = service_api_client.create_service_template(
+                'Untitled',
+                'letter',
+                'Content',
+                service_id,
+                'Title',
+                'normal',
+            )
+            return redirect(url_for(
+                '.view_template',
+                service_id=service_id,
+                template_id=blank_letter['data']['id'],
+            ))
+
         return redirect(url_for(
             '.add_service_template',
             service_id=service_id,