title: WooCommerce [product_categories] shortcode - Missing displayed sub-categories
body: <p>I am using WooCommerce plugin in WordPress, and I have added 20 sub-categories in one parent category. When I want to display all the sub-categories in a page using this shortcode:</p>
  
  <pre><code>[product_categories number="20" parent="0"]
  </code></pre>
  
  <p>It just retrieves 12 of them with no pagination and doesn't display sub-categories.</p>
  
  <p>Why this is happening? <br>
  How can I increase this limit?</p>