Add user signup form and implement signup view; enhance message display in templates

base/templates/base.html

@@ -57,6 +57,7 @@
             </div>
         </header>
         <main class="container">
+            {% for message in messages %}<article class="message {{ message.tags }}">{{ message }}</article>{% endfor %}
             {% block content %}
             {% endblock content %}
         </main>