display label id in sidebar

templates/tagger.html

@@ -91,7 +91,7 @@
               {% for label in labels %}
                 <div class="list-group-item">
                     <div class="input-group">
-                        <span class="input-group-addon" id="id">{{ label.id }}</span>
+                        <span class="input-group-addon" id="id">id: {{ label.id }}</span>
                         {% if label.name %}
                             <text style="background-color:#E5E7E9;" class="form-control custom-control" style="resize:none">{{ label.name }}</text>
                         {% else %}