changes default category name and menu name in the admin

docu_doc_category_labels.php

function custom_docu_doc_category_labels( $category_labels ) {
	$category_labels['name'] = _x( 'My Category', 'taxonomy custom name' , 'my-text-domain' );
	$category_labels['menu_name'] = __( 'My Categories', 'my-text-domain' ); 
	return $category_labels;
}
add_filter( 'docu_doc_category_labels', 'custom_docu_doc_category_labels' );