Update centering

shared/templates/styleguide2/includes/atoms/buttons/round_button_block.html

 {% firstof self.page.url self.link as link %}
 
-<div class="py-4 {% if self.align == 'center' %}flex justify-center items-center max-w-[100ch]{% endif %}">
+
+<div
+  class="
+    {% if page.root_page.content_is_centered %}
+      mx-auto
+    {% endif %}
+    
+    py-4
+    
+    {% if self.align == 'center' %}flex justify-center items-center max-w-[100ch]{% endif %}
+  "
+>
   {% include "styleguide2/includes/atoms/buttons/round_button.html" with url=link size=self.size text=self.title show_arrow_on_hover=self.hoveractive classes=color_classes %}
 </div>