only include the bookmark menu bit in thread view

app/templates/threads/thread.html

@@ -4,6 +4,7 @@
 {%- extends 'base.html' -%}
 {%- block title -%}{{thread.title}}{%- endblock -%}
 {%- block content -%}
+<bitty-8 data-connect="/static/js/bits/bookmark-menu.js"></bitty-8>
 {%- set td -%}
 <ul class="horizontal">
 <li>Started by <a href="{{url_for('users.user_page', username=started_by.username)}}">{{started_by.get_readable_name()}}</a> in topic <a href="{{url_for('topics.topic_by_id', topic_id=topic.id)}}">{{topic.name}}</a></li>