Auto-scroll to item comment form

Scroll up to ensure the from input is not hidden below the navbar.

See https://github.com/twbs/bootstrap/issues/1768

app/static/js/items.js

 $(document).ready(function() {
 
+  // scroll up to avoid having the form input
+  // hidden under the navbar
+  if (location.hash == "#text") {
+    scrollBy(0, -100);
+  }
+
   var converter = new showdown.Converter({
     simplifiedAutoLink: true
   });

app/templates/inventory/view_item.html

@@ -62,7 +62,7 @@
     <div class="card-body item-comment">{{ comment.text }}</div>
   </div>
   {% endfor %}
-  <a class="btn btn-primary" href="{{ url_for('inventory.comment_item', ics_id=item.ics_id) }}">Comment</a>
+  <a class="btn btn-primary" href="{{ url_for('inventory.comment_item', ics_id=item.ics_id) }}#text">Comment</a>
 
   <hr>