title: Add custom product type in woocommerce
body: <p>I am using Woocommerce, I wanted to create a custom product type but I didn't get the way</p>
  
  <p>In Woocommerce there are four product type like</p>
  
  <pre><code> Simple product
   variable product
   grouped product and
   External/Affiliate product
  </code></pre>
  
  <p>I need another custom product type there. is there any way to create a custom product type?</p>