Add parameter captureBeyondViewport to screenshot (#203)

Co-authored-by: Graham Campbell <GrahamCampbell@users.noreply.github.com>

Author: momala454

src/Page.php

@@ -435,6 +435,7 @@ public function getFullPageClip(int $timeout = null): Clip
      *  - format: "png"|"jpg" default "png"
      *  - quality: number from 0 to 100. Only for jpegs
      *  - clip: instance of a Clip to choose an area for the screenshot
+     *  - captureBeyondViewport: whether to capture the screenshot beyond the viewport. Defaults to false
      *
      * @return PageScreenshot
      * @throws CommunicationException
@@ -445,6 +446,10 @@ public function screenshot(array $options = []): PageScreenshot
 
         $screenshotOptions = [];
 
+        if (array_key_exists('captureBeyondViewport', $options)) {
+            $screenshotOptions['captureBeyondViewport'] = $options['captureBeyondViewport'];
+        }
+
         // get format
         if (array_key_exists('format', $options)) {
             $screenshotOptions['format'] = $options['format'];