Add convert to webp to linkit image style

Problem/motivation

Webp is a file format that dramatically improves the file size of images.

Since Linkit creates an image style, it is the only image style used in Drupal CMS that doesn't get the convert to webp action.

While Drupal CMS could add some recipe configurations to update the style from Linkit, it would be a good feature to have for all users of the module because it improves the file size of images displayed.

Proposed resolution

Add convert to webp to the linkit image style.