Support overflow grid

src/invidious/views/playlist.ecr

@@ -24,13 +24,13 @@
     <p><%= playlist.description_html %></p>
 </div>
 
-<% videos.each_slice(4) do |slice| %>
 <div class="pure-g">
+<% videos.each_slice(4) do |slice| %>
     <% slice.each do |item| %>
         <%= rendered "components/item" %>
     <% end %>
-</div> 
 <% end %>
+</div> 
 
 <div class="pure-g h-box">
     <div class="pure-u-1 pure-u-md-1-5">