[collector] can now collect Teile and list them

If a newly entered Teil already exists, we ignore that and do nothing.

"name" could become a primary key...

collector/templates/collector/detail.html

@@ -1,2 +1,17 @@
 <h1>{{ teil.name }}</h1>
 Last Changed: {{ teil.modified }}
+
+<hr>
+
+<form action="{% url 'collector:detail' teil.id %}" method="POST">
+  {% csrf_token %}
+  <fieldset>
+    <legend>
+      <h1>{{ teil.name }}</h1>
+    </legend>
+    {% if error_message %}
+      <p><strong>{{ error_message }}</strong></p>
+    {% endif %}
+  </fieldset>
+<input type="submit" name="submit" value="enter it!">
+</form>

collector/templates/collector/index.html

@@ -15,3 +15,9 @@
   <p>Keine Teile da.</p>
 
 {% endif %}
+
+<form method="POST" action="{% url 'collector:enter' %}">
+  {% csrf_token %}
+  <input type="text" name="new_name" value="">
+  <input type="submit" name="submit" value="add new Teil">
+</form>