title: webp image display black background instead of transparency
body: <p>When upload <code>png</code> image and convert into <code>webp</code> image using <code>rossell-dk plugin</code>. means it display black background instead of transparent background.</p>
  
  <pre><code>$success = WebPConvert\WebPConvert::convert($pathToImages, $pathToWebpImages, [
              // It is not required that you set any options - all have sensible defaults.
              // We set some, for the sake of the example.
              'quality' =&gt; 'auto',
              'max-quality' =&gt; 90,
              'converters' =&gt;  [ 'gd', 'imagick', 'wpc', 'ewww']/*,
              'skip-pngs'=&gt;"0"*/
              //'converters' =&gt; ['cwebp','webp', 'gd', 'imagick', 'wpc', 'ewww'],  
              // Specify conversion methods to use, and their order
          ]);
  </code></pre>