update template, add opt.

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

 {% load wagtailcore_tags %}
 
-<div class="flex gap-3 py-4">
+<div class="flex gap-3 py-4 flex-wrap">
   {% for button in self.buttons %}
     {% include_block button %}
   {% endfor %}