716 books can be on multiple shelves, but only on one shelf for reading status

bookwyrm/templates/snippets/shelf_selector.html

@@ -12,6 +12,7 @@
     <form class="dropdown-item pt-0 pb-0" name="shelve" action="/shelve/" method="post">
         {% csrf_token %}
         <input type="hidden" name="book" value="{{ book.id }}">
+        <input type="hidden" name="change-shelf-from" value={{ current.identifier }}>
         <input type="hidden" name="shelf" value="{{ shelf.identifier }}">
         <button class="button is-fullwidth is-small" type="submit">{{ shelf.name }}</button>
     </form>