Enable taxonomy sorting (tax_position) for default WordPress taxonomies (post - categories etc.)

enable-sorting-default-wp-taxonomies.php

<?php
/*
* Enable drag & drop sorting on default WordPress taxonomies (ie: categories) - (page/post)
*/

add_filter( 'register_taxonomy_args' , 'add_tax_position_support', 9999, 3 );
function add_tax_position_support( $args, $taxonomy, $object_type ) {
	if( 'category' == $taxonomy ) {
		$args['tax_position'] = true;
	}
	return $args;
}