Quick and easy feature requests

1. Can you add a filter check for $post_url in the generate() function, to modify the target link? I can not use WordPress’ post_link filter as I only want it to apply in the carousel.

2. The image sources are hard coded in getSources() to be the WordPress defaults. Can it use get_intermediate_image_sizes() so it will automatically include custom theme images? Easier than using filters.

Great plugin!