Style horizontal break in feed

src/invidious/views/subscriptions.ecr

@@ -23,7 +23,10 @@
         <% end %>
     </div>
 <% end %>
-<hr>
+
+<div class="h-box">
+    <hr>
+</div>
 
 <% videos.each_slice(4) do |slice| %>
     <div class="pure-g">