Add content before and after thumbnail images in WooCommerce product thumbnails

single-product.js

jQuery( document ).ready(
	function( $ ) {
	var newDiv = document.createElement('div');
	$(newDiv).attr('id','slider-nav');
	$(newDiv).attr('class','slider-nav');
	$('.flex-control-nav').wrap('#slider-nav');
	$('.flex-control-nav').wrap(newDiv);
	$('.flex-control-nav').before('<span class="chevron-up"></span>');
	$('.flex-control-nav').after('<span  class="chevron-down"></span>');
}
);

// Related https://wordpress.org/support/topic/add-content-after-product-thumbnail-gallery/