* Register ticket create shortcode
* Outputs the shortcode [ticket_create]
* @since     1.0.0

Renders the shortcode [ticket_create]. The actual shortcode templates can be found in the files inc/shortcodes/ticket-create.php and inc/shortcodes/ticket-create-done.php. The first file renders the form while the second file is used, once the form has been successfully submitted. Both files can be replaced using the filters sts-create-ticket-shortcodefile and sts-create-ticket-done-shortcodefile.