UX: Ensure equal margin around topic search box (#106)

assets/javascripts/discourse/templates/group-topics-list.hbs

@@ -1,3 +1,4 @@
+<div class="topic-search-div">
   <div class="form-horizontal bookmark-search-form">
     {{input type="text"
         value=searchTerm
@@ -5,6 +6,7 @@
         input=(action "onChangeFilter" value="target.value")
         autocomplete="discourse"}}
   </div>
+</div>
 {{#load-more class="paginated-topics-list" selector=".paginated-topics-list .topic-list tr" action=(action "loadMore")}}
   {{basic-assigned-topic-list topicList=model
                               hideCategory=hideCategory

assets/stylesheets/assigns.scss

@@ -137,3 +137,7 @@
     padding: 0 13px;
   }
 }
+
+.topic-search-div {
+  margin-left: 1em;
+}