Change step 1 of tour to only show the template

We’ve made a few changes to the tour recently, without changing the
help text on the left hand side of the screen. So the stuff you see on
the right side of the screen doesn’t quite sync up any more.

This commit adds an extra, introductory page that just shows the
template and a next button, which better matches the ‘every message
starts with a template’ help text.

app/templates/views/templates/start-tour.html

@@ -0,0 +1,21 @@
+{% extends "withnav_template.html" %}
+{% from "components/page-footer.html" import page_footer %}
+{% from "components/textbox.html" import textbox %}
+{% from "components/api-key.html" import api_key %}
+
+{% block service_page_title %}
+  {{ template.name }}
+{% endblock %}
+
+{% block maincolumn_content %}
+
+
+  <h1 class="heading-large">{{ template.name }}</h1>
+
+  {{ template|string }}
+
+  <div class="page-footer">
+    <a href="{{ url_for('.send_test', service_id=current_service.id, template_id=template.id, help=2) }}" class="button">Next</a>
+  </div>
+
+{% endblock %}