title: Generate the product variations SKUs from Woocommerce parent variable SKU
body: <p>In Woocommerce I would like to generate the product variations SKUs from the parent variable product SKU like:</p>
  
  <ul>
  <li>Variable Product sku: 1200<br></li>
  <li>1st Product Variation SKU: 1200-01</li>
  <li>2nd Product Variation SKU: 1200-02</li>
  <li>3rd Product Variation SKU: 1200-03</li>
  <li><em>… and so on …</em></li>
  </ul>
  
  <p>So I need an SKU in the order (and shown in the product page when choosen the variation) like: 1200-01</p>
  
  <p>I can not figure out how to achieve that in woocommerce. I worked with other shop systems before and that was a very basic setting to get the variations running.</p>
  
  <p>Really thankful for any help.</p>